$ crystal --version
Crystal 0.28.0 (2019-04-17)

LLVM: 6.0.1
Default target: x86_64-pc-linux-gnu

$ uname -a
Linux thinkpad 5.0.13-arch1-1-ARCH #1 SMP PREEMPT Sun May 5 18:05:41 UTC 2019 x86_64 GNU/Linux

$ crystal eval 'require "compiler/crystal/**"; print Config.default_target'
Error in /usr/lib/crystal/compiler/crystal/compiler.cr:96: instantiating 'Crystal::Config:Module#default_target()'

    property codegen_target = Config.default_target
                                     ^~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/config.cr:51: instantiating 'runtime_libc()'

          target = Crystal::Codegen::Target.new(target.to_s.sub(default_libc, "-#{runtime_libc}"))
                                                                                  ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/config.cr:59: instantiating 'String.class#build()'

      ldd_version = String.build do |io|
                           ^~~~~

in /usr/lib/crystal/string.cr:268: instantiating 'String::Builder.class#build(Int32)'

    String::Builder.build(capacity) do |builder|
                    ^~~~~

in /usr/lib/crystal/string.cr:268: instantiating 'String::Builder.class#build(Int32)'

    String::Builder.build(capacity) do |builder|
                    ^~~~~

in /usr/lib/crystal/compiler/crystal/config.cr:59: instantiating 'String.class#build()'

      ldd_version = String.build do |io|
                           ^~~~~

in /usr/lib/crystal/compiler/crystal/config.cr:60: instantiating 'Process.class#run(String, Tuple(String))'

        Process.run("ldd", {"--version"}, output: io, error: io)
                ^~~

in /usr/lib/crystal/process.cr:165: instantiating 'new(String, Tuple(String), Nil, Bool, Bool, Process::Redirect, String::Builder, String::Builder, Nil)'

    status = new(command, args, env, clear_env, shell, input, output, error, chdir).wait
             ^~~

in /usr/lib/crystal/kernel.cr:1: expanding macro

{% if flag?(:win32) %}
^

in macro 'macro_94594043149712' /usr/lib/crystal/kernel.cr:1, line 5:

   1.
   2.   require "c/unistd"
   3.
   4.   # The standard input file descriptor. Contains data piped to the program.
>  5.   STDIN  = IO::FileDescriptor.from_stdio(0)
   6.
   7.   # The standard output file descriptor.
   8.   #
   9.   # Typically used to output data and information.
  10.   #
  11.   # When this is a TTY device, `sync` will be true for it
  12.   # at the start of the program.
  13.   STDOUT = IO::FileDescriptor.from_stdio(1)
  14.
  15.   # The standard error file descriptor.
  16.   #
  17.   # Typically used to output error messages and diagnostics.
  18.   #
  19.   # When this is a TTY device, `sync` will be true for it
  20.   # at the start of the program.
  21.   STDERR = IO::FileDescriptor.from_stdio(2)

instantiating 'IO::FileDescriptor.class#from_stdio(Int32)'
in /usr/lib/crystal/io/file_descriptor.cr:28: instantiating 'new(Int32)'

    return new(fd, blocking: true) unless ret == 0
           ^~~

in /usr/lib/crystal/io/file_descriptor.cr:12: instantiating 'GC:Module#add_finalizer(IO::FileDescriptor)'

  def initialize(@fd, blocking = false)
  ^

in /usr/lib/crystal/gc/boehm.cr:121: instantiating 'add_finalizer_impl(IO::FileDescriptor)'

    add_finalizer_impl(object)
    ^~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/gc/boehm.cr:130: instantiating 'IO::FileDescriptor+#finalize()'

      ->(obj, data) { obj.as(T).finalize },
                                ^~~~~~~~

in /usr/lib/crystal/io/file_descriptor.cr:141: instantiating 'close()'

    close rescue nil
    ^~~~~

in /usr/lib/crystal/io/buffered.cr:187: instantiating 'flush()'

    flush if @out_count > 0
    ^~~~~

in /usr/lib/crystal/io/buffered.cr:179: instantiating 'unbuffered_write(Slice(UInt8))'

    unbuffered_write(Slice.new(out_buffer, @out_count)) if @out_count > 0
    ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/crystal/system/unix/file_descriptor.cr:17: instantiating 'evented_write(Slice(UInt8), String)'

    evented_write(slice, "Error writing file") do |slice|
    ^~~~~~~~~~~~~

in /usr/lib/crystal/io/evented.cr:70: instantiating 'loop()'

      loop do
      ^~~~

in /usr/lib/crystal/io/evented.cr:70: instantiating 'loop()'

      loop do
      ^~~~

in /usr/lib/crystal/io/evented.cr:77: instantiating 'wait_writable()'

            wait_writable
            ^~~~~~~~~~~~~

in /usr/lib/crystal/io/evented.cr:136: instantiating 'wait_writable((Time::Span | Nil))'

  protected def wait_writable(timeout = @write_timeout)
            ^

in /usr/lib/crystal/io/evented.cr:137: instantiating 'wait_writable()'

    wait_writable(timeout: timeout) { |err| raise err }
    ^~~~~~~~~~~~~

in /usr/lib/crystal/io/evented.cr:143: instantiating 'add_write_event((Time::Span | Nil))'

    add_write_event(timeout)
    ^~~~~~~~~~~~~~~

in /usr/lib/crystal/io/evented.cr:153: instantiating 'Crystal::EventLoop:Module#create_fd_write_event(IO::FileDescriptor+)'

    event = @write_event ||= Crystal::EventLoop.create_fd_write_event(self)
                                                ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/crystal/event_loop.cr:32: instantiating 'IO::FileDescriptor+#resume_write()'

        io_ref.resume_write
               ^~~~~~~~~~~~

in /usr/lib/crystal/io/evented.cr:107: instantiating 'resume_write(Bool)'

  def resume_write(timed_out = false)
  ^

in /usr/lib/crystal/io/evented.cr:111: instantiating 'Fiber#resume()'

      writer.resume
             ^~~~~~

in /usr/lib/crystal/fiber.cr:119: instantiating 'Crystal::Scheduler.class#resume(Fiber)'

    Crystal::Scheduler.resume(self)
                       ^~~~~~

in /usr/lib/crystal/crystal/scheduler.cr:30: instantiating 'Crystal::Scheduler#resume(Fiber)'

    Thread.current.scheduler.resume(fiber)
                             ^~~~~~

in /usr/lib/crystal/crystal/scheduler.cr:60: instantiating 'validate_resumable(Fiber)'

    validate_resumable(fiber)
    ^~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/crystal/scheduler.cr:80: instantiating 'fatal_resume_error(Fiber, String)'

      fatal_resume_error(fiber, "tried to resume a dead fiber")
      ^~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/crystal/scheduler.cr:102: instantiating 'exit(Int32)'

    exit 1
    ^~~~

in /usr/lib/crystal/kernel.cr:510: instantiating 'AtExitHandlers:Module#run(Int32)'

  status = AtExitHandlers.run status
                          ^~~

in /usr/lib/crystal/kernel.cr:458: instantiating 'String::Builder#<<(Exception+)'

          STDERR.puts "Error running at_exit handler: #{handler_ex}"
                      ^

in /usr/lib/crystal/io.cr:184: instantiating 'Exception+#to_s(String::Builder)'

    obj.to_s self
        ^~~~

in /usr/lib/crystal/compiler/crystal/exception.cr:11: instantiating 'to_s_with_source(Nil, String::Builder)'

      to_s_with_source(nil, io)
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/exception.cr:178: instantiating 'append_to_s(Nil, String::Builder)'

      append_to_s(source, io)
      ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/exception.cr:202: instantiating 'String::Builder#<<((Crystal::Type | Nil))'

        io << "#{@owner} trace:"
              ^

in /usr/lib/crystal/io.cr:184: instantiating '(Crystal::Type | Nil)#to_s(String::Builder)'

    obj.to_s self
        ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:694: instantiating 'to_s_with_options(String::Builder)'

      to_s_with_options(io)
      ^~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2981: instantiating 'Array(Crystal::Type)#join(String, String::Builder)'

      union_types.join(" | ", io) do |type|
                  ^~~~

in /usr/lib/crystal/enumerable.cr:696: instantiating 'each_with_index()'

    each_with_index do |elem, i|
    ^~~~~~~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/enumerable.cr:696: instantiating 'each_with_index()'

    each_with_index do |elem, i|
    ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2981: instantiating 'Array(Crystal::Type)#join(String, String::Builder)'

      union_types.join(" | ", io) do |type|
                  ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2982: instantiating 'Crystal::Type+#devirtualize()'

        type = type.devirtualize unless codegen
                    ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:244: instantiating 'Crystal::Type+#metaclass()'

        self.base_type.metaclass
                       ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:97: instantiating 'Crystal::MetaclassType.class#new(Crystal::Program, Crystal::Type+)'

      metaclass = MetaclassType.new(program, self)
                                ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:2705: instantiating 'initialize(Crystal::Program, Crystal::Type+, Nil, Nil)'

    def initialize(program, @instance_type : Type, super_class = nil, name = nil)
    ^

in /usr/lib/crystal/compiler/crystal/types.cr:2709: instantiating 'Crystal::NonGenericClassType#metaclass()'

                        program.enum.metaclass
                                     ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:97: instantiating 'Crystal::MetaclassType.class#new(Crystal::Program, Crystal::NonGenericClassType)'

      metaclass = MetaclassType.new(program, self)
                                ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:2705: instantiating 'initialize(Crystal::Program, Crystal::NonGenericClassType, Nil, Nil)'

    def initialize(program, @instance_type : Type, super_class = nil, name = nil)
    ^

in /usr/lib/crystal/compiler/crystal/types.cr:2720: instantiating 'super(Crystal::Program, Crystal::Program, String, Crystal::Type+)'

      super(program, program, name, super_class)
      ^~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1147: instantiating 'initialize(Crystal::Program, Crystal::Program, String, Crystal::Type+, Bool)'

    def initialize(program, namespace, name, @superclass, add_subclass = true)
    ^

in /usr/lib/crystal/compiler/crystal/types.cr:1151: instantiating 'force_add_subclass()'

      force_add_subclass if add_subclass
      ^~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1173: instantiating '(Crystal::Type | Nil)#try()'

      superclass.try &.add_subclass(self)
                 ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1173: instantiating '(Crystal::Type | Nil)#try()'

      superclass.try &.add_subclass(self)
                 ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1173: instantiating 'Crystal::Type+#add_subclass(Crystal::MetaclassType)'

      superclass.try &.add_subclass(self)
                       ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1972: instantiating 'notify_subclass_added()'

      notify_subclass_added
      ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:976: instantiating '(Array(Crystal::Call) | Nil)#try()'

      @subclass_observers.try &.dup.each &.on_new_subclass
                          ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:976: instantiating '(Array(Crystal::Call) | Nil)#try()'

      @subclass_observers.try &.dup.each &.on_new_subclass
                          ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:976: instantiating 'Array(Crystal::Call)#each()'

      @subclass_observers.try &.dup.each &.on_new_subclass
                                    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:976: instantiating 'Array(Crystal::Call)#each()'

      @subclass_observers.try &.dup.each &.on_new_subclass
                                    ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:976: instantiating 'Crystal::Call#on_new_subclass()'

      @subclass_observers.try &.dup.each &.on_new_subclass
                                           ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:671: instantiating 'recalculate()'

    recalculate
    ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:45: instantiating 'recalculate_lib_call(Crystal::LibType)'

      return recalculate_lib_call obj_type
             ^~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/lib.cr:3: instantiating 'replace_splats()'

    replace_splats
    ^~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:521: instantiating 'Array(Crystal::ASTNode)#each_with_index()'

    args.each_with_index do |arg, i|
         ^~~~~~~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:521: instantiating 'Array(Crystal::ASTNode)#each_with_index()'

    args.each_with_index do |arg, i|
         ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:529: instantiating 'Array(Crystal::Type)#each_with_index()'

        arg_type.tuple_types.each_with_index do |tuple_type, index|
                             ^~~~~~~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:529: instantiating 'Array(Crystal::Type)#each_with_index()'

        arg_type.tuple_types.each_with_index do |tuple_type, index|
                             ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/call.cr:531: instantiating 'Crystal::NumberLiteral#type=(Crystal::IntegerType)'

          num.type = program.int32
              ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:86: instantiating 'set_type(Crystal::IntegerType)'

      set_type(type)
      ^~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:37: instantiating 'Crystal::IntegerType#implements?(Crystal::Type+)'

      if !type.no_return? && (freeze_type = @freeze_type) && !type.implements?(freeze_type)
                                                                   ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:253: instantiating 'Crystal::Type+#remove_alias()'

      other_type = other_type.remove_alias
                              ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2569: instantiating 'process_value()'

      process_value
      ^~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2605: instantiating 'Crystal::ModuleType+#lookup_type(Crystal::ASTNode+)'

      @aliased_type = namespace.lookup_type(@value,
                                ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:45: instantiating 'Crystal::Type::TypeLookup#lookup(Crystal::ASTNode+)'

    TypeLookup.new(self, self_type, true, allow_typeof, free_vars, find_root_generic_type_parameters).lookup(node).not_nil!
                                                                                                      ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:83: instantiating 'lookup_type_var?(Crystal::Path)'

      type_var = lookup_type_var?(node)
                 ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:120: instantiating 'Crystal::Type+#lookup_path(Array(String))'

          type = free_var.lookup_path(node.names[1..-1], lookup_in_namespace: false, location: node.location)
                          ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:175: expanding macro

    delegate lookup_path, to: instance_type
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 4:

   1.
   2.
   3.         def lookup_path(*args, **options)
>  4.           instance_type.lookup_path(*args, **options)
   5.         end
   6.
   7.
   8.           def lookup_path(*args, **options)
   9.             instance_type.lookup_path(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.

instantiating 'Crystal::VirtualType#lookup_path(Tuple(Array(String)), NamedTuple(lookup_in_namespace: Bool, location: Crystal::Location | Nil))'
in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:171: expanding macro

    delegate lookup_path, to: base_type
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 4:

   1.
   2.
   3.         def lookup_path(*args, **options)
>  4.           base_type.lookup_path(*args, **options)
   5.         end
   6.
   7.
   8.           def lookup_path(*args, **options)
   9.             base_type.lookup_path(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.

instantiating 'Crystal::Type+#lookup_path(Tuple(Array(String)), NamedTuple(lookup_in_namespace: Bool, location: Crystal::Location | Nil))'
in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:167: expanding macro

    delegate lookup_path, to: instance_type
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 4:

   1.
   2.
   3.         def lookup_path(*args, **options)
>  4.           instance_type.lookup_path(*args, **options)
   5.         end
   6.
   7.
   8.           def lookup_path(*args, **options)
   9.             instance_type.lookup_path(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.

instantiating 'Crystal::Type+#lookup_path(Tuple(Array(String)), NamedTuple(lookup_in_namespace: Bool, location: Crystal::Location | Nil))'
in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:163: expanding macro

    delegate lookup_path, to: instance_type
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 4:

   1.
   2.
   3.         def lookup_path(*args, **options)
>  4.           instance_type.lookup_path(*args, **options)
   5.         end
   6.
   7.
   8.           def lookup_path(*args, **options)
   9.             instance_type.lookup_path(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.

instantiating 'Crystal::Type+#lookup_path(Tuple(Array(String)), NamedTuple(lookup_in_namespace: Bool, location: Crystal::Location | Nil))'
in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:155: expanding macro

    delegate lookup_path, to: typedef
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 4:

   1.
   2.
   3.         def lookup_path(*args, **options)
>  4.           typedef.lookup_path(*args, **options)
   5.         end
   6.
   7.
   8.           def lookup_path(*args, **options)
   9.             typedef.lookup_path(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.

instantiating 'Crystal::Type+#lookup_path(Tuple(Array(String)), NamedTuple(lookup_in_namespace: Bool, location: Crystal::Location | Nil))'
in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:159: expanding macro

    delegate lookup_path, to: instance_type
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 4:

   1.
   2.
   3.         def lookup_path(*args, **options)
>  4.           instance_type.lookup_path(*args, **options)
   5.         end
   6.
   7.
   8.           def lookup_path(*args, **options)
   9.             instance_type.lookup_path(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.

instantiating 'Crystal::Type+#lookup_path(Tuple(Array(String)), NamedTuple(lookup_in_namespace: Bool, location: Crystal::Location | Nil))'
in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:42: instantiating 'lookup_path(Array(String), Bool, Bool, (Crystal::Location | Nil))'

    def lookup_path(names : Array(String), lookup_in_namespace = true, include_private = false, location = nil) : Type | ASTNode | Nil
    ^

in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:44: instantiating 'Array(String)#each_with_index()'

      names.each_with_index do |name, i|
            ^~~~~~~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:44: instantiating 'Array(String)#each_with_index()'

      names.each_with_index do |name, i|
            ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:47: instantiating 'Crystal::Type+#lookup_path_item(String)'

        type = type.lookup_path_item(name, lookup_in_namespace: lookup_in_namespace && i == 0, include_private: i == 0 || include_private, location: location)
                    ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/path_lookup.cr:138: instantiating 'Crystal::Program#tuple_of(Array(Crystal::Type))'

        return program.tuple_of(union_types)
                       ^~~~~~~~

in /usr/lib/crystal/compiler/crystal/program.cr:309: instantiating 'Crystal::TupleType#instantiate(Array(Crystal::ASTNode | Crystal::Type))'

      tuple.instantiate(type_vars)
            ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2255: instantiating 'Crystal::TupleInstanceType.class#new(Crystal::Program, Array(Crystal::Type))'

      instance = TupleInstanceType.new(program, types)
                                   ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:2277: instantiating 'Crystal::Var#bind_to(Crystal::Var)'

      var.bind_to var
          ^~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:92: instantiating 'bind(Crystal::Var)'

      bind(node) do |dependencies|
      ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:124: instantiating 'Crystal::Type.class#merge(Array(Crystal::ASTNode))'

        new_type = Type.merge dependencies
                        ^~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:147: instantiating '(Crystal::ASTNode | Nil)#try()'

      nodes.find(&.type?).try &.type.program.type_merge(nodes)
                          ^~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:147: instantiating '(Crystal::ASTNode | Nil)#try()'

      nodes.find(&.type?).try &.type.program.type_merge(nodes)
                          ^~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:147: instantiating 'Crystal::Program#type_merge(Array(Crystal::ASTNode))'

      nodes.find(&.type?).try &.type.program.type_merge(nodes)
                                             ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:34: instantiating 'combined_union_of(Array(Crystal::Type))'

      combined_union_of compact_types(nodes, &.type?)
      ^~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:117: instantiating 'type_combine(Array(Crystal::Type))'

        combined_types = type_combine types
                         ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:125: instantiating 'Array(Crystal::Type)#each()'

      types.each do |t2|
            ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:125: instantiating 'Array(Crystal::Type)#each()'

      types.each do |t2|
            ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:126: instantiating 'Array(Crystal::Type)#all?()'

        not_found = all_types.all? do |t1|
                              ^~~~

in /usr/lib/crystal/enumerable.cr:47: instantiating 'each()'

    each { |e| return false unless yield e }
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:47: instantiating 'each()'

    each { |e| return false unless yield e }
    ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:126: instantiating 'Array(Crystal::Type)#all?()'

        not_found = all_types.all? do |t1|
                              ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:127: instantiating 'Crystal::Type+#common_ancestor(Crystal::Type+)'

          ancestor = t1.common_ancestor(t2)
                        ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:267: instantiating 'Crystal::Type+#common_ancestor((Crystal::MetaclassType | Crystal::VirtualMetaclassType))'

      common = instance_type.base_type.metaclass.common_ancestor(other)
                                                 ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:261: instantiating 'Crystal::Type+#common_ancestor((Crystal::MetaclassType | Crystal::VirtualMetaclassType))'

      base_type.common_ancestor(other)
                ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:248: instantiating 'Crystal::Type+#common_ancestor(Crystal::Type+)'

      common = instance_type.common_ancestor(other.instance_type)
                             ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:261: instantiating 'Crystal::Type+#common_ancestor(Crystal::Type+)'

      base_type.common_ancestor(other)
                ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:248: instantiating 'Crystal::Type+#common_ancestor(Crystal::Type+)'

      common = instance_type.common_ancestor(other.instance_type)
                             ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_merge.cr:183: instantiating 'Crystal::Type+#implements?(Crystal::GenericModuleInstanceType)'

      if other.implements?(self)
               ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:3135: expanding macro

    delegate leaf?, superclass, lookup_first_def, lookup_defs,
    ^

in macro 'delegate' /usr/lib/crystal/object.cr:1208, line 172:

   1.
   2.
   3.         def leaf?(*args, **options)
   4.           base_type.leaf?(*args, **options)
   5.         end
   6.
   7.
   8.           def leaf?(*args, **options)
   9.             base_type.leaf?(*args, **options) do |*yield_args|
  10.               yield *yield_args
  11.             end
  12.           end
  13.
  14.
  15.
  16.
  17.         def superclass(*args, **options)
  18.           base_type.superclass(*args, **options)
  19.         end
  20.
  21.
  22.           def superclass(*args, **options)
  23.             base_type.superclass(*args, **options) do |*yield_args|
  24.               yield *yield_args
  25.             end
  26.           end
  27.
  28.
  29.
  30.
  31.         def lookup_first_def(*args, **options)
  32.           base_type.lookup_first_def(*args, **options)
  33.         end
  34.
  35.
  36.           def lookup_first_def(*args, **options)
  37.             base_type.lookup_first_def(*args, **options) do |*yield_args|
  38.               yield *yield_args
  39.             end
  40.           end
  41.
  42.
  43.
  44.
  45.         def lookup_defs(*args, **options)
  46.           base_type.lookup_defs(*args, **options)
  47.         end
  48.
  49.
  50.           def lookup_defs(*args, **options)
  51.             base_type.lookup_defs(*args, **options) do |*yield_args|
  52.               yield *yield_args
  53.             end
  54.           end
  55.
  56.
  57.
  58.
  59.         def lookup_defs_with_modules(*args, **options)
  60.           base_type.lookup_defs_with_modules(*args, **options)
  61.         end
  62.
  63.
  64.           def lookup_defs_with_modules(*args, **options)
  65.             base_type.lookup_defs_with_modules(*args, **options) do |*yield_args|
  66.               yield *yield_args
  67.             end
  68.           end
  69.
  70.
  71.
  72.
  73.         def lookup_instance_var(*args, **options)
  74.           base_type.lookup_instance_var(*args, **options)
  75.         end
  76.
  77.
  78.           def lookup_instance_var(*args, **options)
  79.             base_type.lookup_instance_var(*args, **options) do |*yield_args|
  80.               yield *yield_args
  81.             end
  82.           end
  83.
  84.
  85.
  86.
  87.         def lookup_instance_var?(*args, **options)
  88.           base_type.lookup_instance_var?(*args, **options)
  89.         end
  90.
  91.
  92.           def lookup_instance_var?(*args, **options)
  93.             base_type.lookup_instance_var?(*args, **options) do |*yield_args|
  94.               yield *yield_args
  95.             end
  96.           end
  97.
  98.
  99.
 100.
 101.         def index_of_instance_var(*args, **options)
 102.           base_type.index_of_instance_var(*args, **options)
 103.         end
 104.
 105.
 106.           def index_of_instance_var(*args, **options)
 107.             base_type.index_of_instance_var(*args, **options) do |*yield_args|
 108.               yield *yield_args
 109.             end
 110.           end
 111.
 112.
 113.
 114.
 115.         def lookup_macro(*args, **options)
 116.           base_type.lookup_macro(*args, **options)
 117.         end
 118.
 119.
 120.           def lookup_macro(*args, **options)
 121.             base_type.lookup_macro(*args, **options) do |*yield_args|
 122.               yield *yield_args
 123.             end
 124.           end
 125.
 126.
 127.
 128.
 129.         def lookup_macros(*args, **options)
 130.           base_type.lookup_macros(*args, **options)
 131.         end
 132.
 133.
 134.           def lookup_macros(*args, **options)
 135.             base_type.lookup_macros(*args, **options) do |*yield_args|
 136.               yield *yield_args
 137.             end
 138.           end
 139.
 140.
 141.
 142.
 143.         def all_instance_vars(*args, **options)
 144.           base_type.all_instance_vars(*args, **options)
 145.         end
 146.
 147.
 148.           def all_instance_vars(*args, **options)
 149.             base_type.all_instance_vars(*args, **options) do |*yield_args|
 150.               yield *yield_args
 151.             end
 152.           end
 153.
 154.
 155.
 156.
 157.         def abstract?(*args, **options)
 158.           base_type.abstract?(*args, **options)
 159.         end
 160.
 161.
 162.           def abstract?(*args, **options)
 163.             base_type.abstract?(*args, **options) do |*yield_args|
 164.               yield *yield_args
 165.             end
 166.           end
 167.
 168.
 169.
 170.
 171.         def implements?(*args, **options)
>172.           base_type.implements?(*args, **options)
 173.         end
 174.
 175.
 176.           def implements?(*args, **options)
 177.             base_type.implements?(*args, **options) do |*yield_args|
 178.               yield *yield_args
 179.             end
 180.           end
 181.
 182.
 183.
 184.
 185.         def covariant?(*args, **options)
 186.           base_type.covariant?(*args, **options)
 187.         end
 188.
 189.
 190.           def covariant?(*args, **options)
 191.             base_type.covariant?(*args, **options) do |*yield_args|
 192.               yield *yield_args
 193.             end
 194.           end
 195.
 196.
 197.
 198.
 199.         def ancestors(*args, **options)
 200.           base_type.ancestors(*args, **options)
 201.         end
 202.
 203.
 204.           def ancestors(*args, **options)
 205.             base_type.ancestors(*args, **options) do |*yield_args|
 206.               yield *yield_args
 207.             end
 208.           end
 209.
 210.
 211.
 212.
 213.         def struct?(*args, **options)
 214.           base_type.struct?(*args, **options)
 215.         end
 216.
 217.
 218.           def struct?(*args, **options)
 219.             base_type.struct?(*args, **options) do |*yield_args|
 220.               yield *yield_args
 221.             end
 222.           end
 223.
 224.
 225.
 226.
 227.         def type_var?(*args, **options)
 228.           base_type.type_var?(*args, **options)
 229.         end
 230.
 231.
 232.           def type_var?(*args, **options)
 233.             base_type.type_var?(*args, **options) do |*yield_args|
 234.               yield *yield_args
 235.             end
 236.           end
 237.
 238.
 239.
 240.

instantiating 'Crystal::Type+#implements?(Tuple(Crystal::GenericModuleInstanceType), NamedTuple())'
in /usr/lib/crystal/compiler/crystal/types.cr:2945: instantiating 'Array(Crystal::Type)#all?()'

      self == other_type || union_types.all?(&.implements?(other_type))
                                        ^~~~

in /usr/lib/crystal/enumerable.cr:47: instantiating 'each()'

    each { |e| return false unless yield e }
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:47: instantiating 'each()'

    each { |e| return false unless yield e }
    ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2945: instantiating 'Array(Crystal::Type)#all?()'

      self == other_type || union_types.all?(&.implements?(other_type))
                                        ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2945: instantiating 'Crystal::Type+#implements?(Crystal::GenericModuleInstanceType)'

      self == other_type || union_types.all?(&.implements?(other_type))
                                               ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2428: instantiating 'super(Crystal::GenericModuleInstanceType)'

        super
        ^~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1891: instantiating 'super(Crystal::GenericModuleInstanceType)'

      super || generic_type.implements?(other_type)
      ^~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:264: instantiating 'parents()'

        parents.try &.any? &.implements?(other_type)
        ^~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1840: instantiating 'Array(Crystal::Type)#try()'

      generic_type.parents.try &.map do |parent|
                           ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1840: instantiating 'Array(Crystal::Type)#try()'

      generic_type.parents.try &.map do |parent|
                           ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1841: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::NamedTupleInstanceType)'

        parent.replace_type_parameters(self)
               ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:3199: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::NamedTupleInstanceType)'

      base_type.replace_type_parameters(instance).virtual_type
                ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2950: instantiating 'Array(Crystal::Type)#each()'

      union_types.each do |type|
                  ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2950: instantiating 'Array(Crystal::Type)#each()'

      union_types.each do |type|
                  ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2967: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::NamedTupleInstanceType)'

          new_union_types << type.replace_type_parameters(instance)
                                  ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2442: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::NamedTupleInstanceType)'

        NamedArgumentType.new(entry.name, entry.type.replace_type_parameters(instance))
                                                     ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2330: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::NamedTupleInstanceType)'

      new_tuple_types = tuple_types.map &.replace_type_parameters(instance)
                                          ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1886: instantiating 'Crystal::GenericType#instantiate(Array(Crystal::ASTNode | Crystal::Type))'

      generic_type.instantiate(new_type_vars)
                   ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2176: instantiating 'Crystal::ProcInstanceType#after_initialize()'

      instance.after_initialize
               ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1963: instantiating 'ancestors()'

      ancestors.each do |ancestor|
      ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:365: instantiating 'collect_ancestors(Array(Crystal::Type))'

      collect_ancestors(ancestors)
      ^~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:370: instantiating 'parents()'

      parents.try &.each do |parent|
      ^~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1840: instantiating 'Array(Crystal::Type)#try()'

      generic_type.parents.try &.map do |parent|
                           ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1840: instantiating 'Array(Crystal::Type)#try()'

      generic_type.parents.try &.map do |parent|
                           ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1841: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::ProcInstanceType)'

        parent.replace_type_parameters(self)
               ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:3199: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::ProcInstanceType)'

      base_type.replace_type_parameters(instance).virtual_type
                ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2950: instantiating 'Array(Crystal::Type)#each()'

      union_types.each do |type|
                  ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2950: instantiating 'Array(Crystal::Type)#each()'

      union_types.each do |type|
                  ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2967: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::ProcInstanceType)'

          new_union_types << type.replace_type_parameters(instance)
                                  ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2442: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::ProcInstanceType)'

        NamedArgumentType.new(entry.name, entry.type.replace_type_parameters(instance))
                                                     ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2330: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::ProcInstanceType)'

      new_tuple_types = tuple_types.map &.replace_type_parameters(instance)
                                          ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1886: instantiating 'Crystal::GenericType#instantiate(Array(Crystal::ASTNode | Crystal::Type))'

      generic_type.instantiate(new_type_vars)
                   ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1491: instantiating 'instantiated_generic_superclass(Crystal::GenericClassInstanceType+)'

        instance.superclass = instantiated_generic_superclass(instance)
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1591: instantiating 'Crystal::GenericClassInstanceType+#replace_type_parameters(Crystal::GenericClassInstanceType+)'

        superclass = superclass.replace_type_parameters(instance)
                                ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2442: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::GenericClassInstanceType+)'

        NamedArgumentType.new(entry.name, entry.type.replace_type_parameters(instance))
                                                     ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:3199: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::GenericClassInstanceType+)'

      base_type.replace_type_parameters(instance).virtual_type
                ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2950: instantiating 'Array(Crystal::Type)#each()'

      union_types.each do |type|
                  ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2950: instantiating 'Array(Crystal::Type)#each()'

      union_types.each do |type|
                  ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2953: instantiating 'Crystal::TypeParameter#solve(Crystal::GenericClassInstanceType+)'

          replacement = type.solve(instance)
                             ^~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1651: instantiating 'Crystal::GenericClassInstanceType+#ancestors()'

        ancestor = instance.ancestors.find { |ancestor| ancestor.is_a?(GenericInstanceType) && ancestor.generic_type == owner }.as(GenericInstanceType)
                            ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:365: instantiating 'collect_ancestors(Array(Crystal::Type))'

      collect_ancestors(ancestors)
      ^~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:370: instantiating 'parents()'

      parents.try &.each do |parent|
      ^~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1840: instantiating 'Array(Crystal::Type)#try()'

      generic_type.parents.try &.map do |parent|
                           ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1840: instantiating 'Array(Crystal::Type)#try()'

      generic_type.parents.try &.map do |parent|
                           ^~~

in /usr/lib/crystal/compiler/crystal/types.cr:1841: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::GenericClassInstanceType+)'

        parent.replace_type_parameters(self)
               ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2330: instantiating 'Crystal::Type+#replace_type_parameters(Crystal::GenericClassInstanceType+)'

      new_tuple_types = tuple_types.map &.replace_type_parameters(instance)
                                          ^~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1886: instantiating 'Crystal::GenericType#instantiate(Array(Crystal::ASTNode | Crystal::Type))'

      generic_type.instantiate(new_type_vars)
                   ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1494: instantiating 'Hash(String, Crystal::MetaTypeVar)+#each()'

      self.instance_vars.each do |name, ivar|
                         ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1494: instantiating 'Hash(String, Crystal::MetaTypeVar)+#each()'

      self.instance_vars.each do |name, ivar|
                         ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1505: instantiating 'Crystal::GenericModuleInstanceType#declare_instance_var(String, Crystal::Type+, (Hash(Crystal::AnnotationType, Array(Crystal::Annotation)) | Nil))'

        instance.declare_instance_var(name, instance_var_type, ivar.annotations)
                 ^~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:298: instantiating 'Crystal::MetaTypeVar#type=(Crystal::Type+)'

      var.type = type
          ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::MetaTypeVar)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/filters.cr:13: instantiating 'Crystal::TypeFilter+#apply(Crystal::Type+)'

        self.type = @filter.apply(from_type)
                            ^~~~~

in /usr/lib/crystal/compiler/crystal/semantic/filters.cr:216: instantiating 'Crystal::Type+#try()'

      other.try &.filter_by_responds_to(@name)
            ^~~

in /usr/lib/crystal/compiler/crystal/semantic/filters.cr:216: instantiating 'Crystal::Type+#try()'

      other.try &.filter_by_responds_to(@name)
            ^~~

in /usr/lib/crystal/compiler/crystal/semantic/filters.cr:216: instantiating 'Crystal::Type+#filter_by_responds_to(String)'

      other.try &.filter_by_responds_to(@name)
                  ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:3077: instantiating 'Crystal::Type+#filter_by_responds_to(String)'

      filtered = virtual_lookup(base_type).filter_by_responds_to(name)
                                           ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:3077: instantiating 'Crystal::Type+#filter_by_responds_to(String)'

      filtered = virtual_lookup(base_type).filter_by_responds_to(name)
                                           ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2919: instantiating 'Array(Crystal::Type)#compact_map()'

      filtered_types = union_types.compact_map &.filter_by_responds_to(name)
                                   ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2919: instantiating 'Array(Crystal::Type)#compact_map()'

      filtered_types = union_types.compact_map &.filter_by_responds_to(name)
                                   ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2919: instantiating 'Crystal::Type+#filter_by_responds_to(String)'

      filtered_types = union_types.compact_map &.filter_by_responds_to(name)
                                                 ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:2798: instantiating 'Crystal::GenericType#metaclass()'

      if instance_type.generic_type.metaclass.filter_by_responds_to(name)
                                    ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:98: instantiating 'initialize_metaclass(Crystal::MetaclassType)'

      initialize_metaclass(metaclass)
      ^~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:1765: instantiating 'Crystal::MetaclassType#add_def(Crystal::Def)'

      metaclass.add_def Def.new("allocate", body: Primitive.new("allocate"))
                ^~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:831: instantiating 'Array(Crystal::DefWithMetadata)#each_with_index()'

      list.each_with_index do |ex_item, i|
           ^~~~~~~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/compiler/crystal/types.cr:831: instantiating 'Array(Crystal::DefWithMetadata)#each_with_index()'

      list.each_with_index do |ex_item, i|
           ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/types.cr:832: instantiating 'Crystal::DefWithMetadata#restriction_of?(Crystal::DefWithMetadata, Crystal::MetaclassType)'

        if item.restriction_of?(ex_item, self)
                ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:100: instantiating 'Range(Int32, Int32)#each()'

      (0...min).each do |index|
                ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:100: instantiating 'Range(Int32, Int32)#each()'

      (0...min).each do |index|
                ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:111: instantiating '(Crystal::ASTNode | Crystal::Type)#restriction_of?((Crystal::ASTNode | Crystal::Type), Crystal::MetaclassType)'

          return false unless self_type.restriction_of?(other_type, owner)
                                        ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:375: instantiating 'Crystal::ASTNode+#restriction_of?(Crystal::ASTNode+, Crystal::MetaclassType)'

      name.restriction_of?(other.name, owner)
           ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:285: instantiating 'Array(Crystal::ASTNode)#all?()'

      types.all? &.restriction_of?(other, owner)
            ^~~~

in /usr/lib/crystal/enumerable.cr:47: instantiating 'each()'

    each { |e| return false unless yield e }
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:47: instantiating 'each()'

    each { |e| return false unless yield e }
    ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:285: instantiating 'Array(Crystal::ASTNode)#all?()'

      types.all? &.restriction_of?(other, owner)
            ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:285: instantiating 'Crystal::ASTNode+#restriction_of?(Crystal::Path, Crystal::MetaclassType)'

      types.all? &.restriction_of?(other, owner)
                   ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/restrictions.cr:301: instantiating 'Crystal::MetaclassType#lookup_type?(Crystal::Generic)'

      self_type = owner.lookup_type?(self)
                        ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:50: instantiating 'Crystal::Type::TypeLookup#lookup(Crystal::Generic)'

    TypeLookup.new(self, self_type, false, allow_typeof, free_vars, find_root_generic_type_parameters).lookup(node)
                                                                                                       ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:162: instantiating 'lookup(Crystal::ASTNode+)'

      type = lookup(node.name)
             ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:142: instantiating 'lookup(Crystal::ASTNode+)'

        type = lookup(ident)
               ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:154: instantiating 'lookup(Crystal::ASTNode+)'

      type = lookup(node.name)
             ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:293: instantiating 'Array(Crystal::ASTNode)#each()'

        inputs.each do |input|
               ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:293: instantiating 'Array(Crystal::ASTNode)#each()'

        inputs.each do |input|
               ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:295: instantiating 'in_generic_args()'

            type = in_generic_args { lookup(input.exp) }
                   ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:295: instantiating 'in_generic_args()'

            type = in_generic_args { lookup(input.exp) }
                   ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:295: instantiating 'lookup(Crystal::ASTNode+)'

            type = in_generic_args { lookup(input.exp) }
                                     ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_lookup.cr:367: instantiating 'Crystal::MainVisitor.class#new(Crystal::Program, Hash(String, Crystal::MetaVar))'

      visitor = MainVisitor.new(program, meta_vars)
                            ^~~

in /usr/lib/crystal/compiler/crystal/semantic/main_visitor.cr:115: instantiating 'initialize(Crystal::Program, Hash(String, Crystal::MetaVar), Nil, Nil)'

    def initialize(program, vars = MetaVars.new, @typed_def = nil, meta_vars = nil)
    ^

in /usr/lib/crystal/compiler/crystal/semantic/main_visitor.cr:137: instantiating 'Hash(String, Crystal::MetaVar)#each()'

        vars.each do |name, var|
             ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/main_visitor.cr:137: instantiating 'Hash(String, Crystal::MetaVar)#each()'

        vars.each do |name, var|
             ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/main_visitor.cr:139: instantiating 'Crystal::MetaVar#bind_to(Crystal::MetaVar)'

          meta_var.bind_to(var)
                   ^~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:92: instantiating 'bind(Crystal::MetaVar)'

      bind(node) do |dependencies|
      ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:133: instantiating 'propagate()'

      propagate
      ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:202: instantiating 'notify_observers()'

        notify_observers
        ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::MetaVar)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/filters.cr:13: instantiating 'Crystal::TypeFilteredNode#type=((Crystal::Type | Nil))'

        self.type = @filter.apply(from_type)
             ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::TypeFilteredNode)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:725: instantiating 'Array(Crystal::Var)#each_with_index()'

      block.args.each_with_index do |arg, i|
                 ^~~~~~~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/enumerable.cr:405: instantiating 'each()'

    each do |elem|
    ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:725: instantiating 'Array(Crystal::Var)#each_with_index()'

      block.args.each_with_index do |arg, i|
                 ^~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:732: instantiating 'Crystal::Var+#type=(Crystal::Type+)'

          arg.type = arg_type
              ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::Var+)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:285: instantiating 'propagate()'

      propagate
      ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:202: instantiating 'notify_observers()'

        notify_observers
        ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::TypeOf)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:394: instantiating 'Crystal::NilableCast#type=(Crystal::Type+)'

      self.type = filtered_type.program.nilable(filtered_type)
           ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::NilableCast)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:355: instantiating 'Crystal::Cast#type=(Crystal::Type+)'

      self.type = filtered_type.virtual_type
           ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::Cast)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:318: instantiating 'Crystal::Union#type=((Crystal::Type | Nil))'

        self.type = program.type_merge_union_of(computed_types)
             ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::Union)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:416: instantiating 'Crystal::ProcLiteral#type=(Crystal::Type+)'

      self.type = self.def.type.program.proc_of(types)
           ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:87: instantiating 'notify_observers()'

      notify_observers
      ^~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

      @observers.try &.each &.update self
                 ^~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Array(Crystal::ASTNode)#each()'

      @observers.try &.each &.update self
                       ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:174: instantiating 'Crystal::ASTNode+#update(Crystal::ProcLiteral)'

      @observers.try &.each &.update self
                              ^~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:472: instantiating 'Array(Crystal::ASTNode)#each()'

        type_vars.each do |node|
                  ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:472: instantiating 'Array(Crystal::ASTNode)#each()'

        type_vars.each do |node|
                  ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/bindings.cr:508: instantiating 'Crystal::MainVisitor#interpret_enum_value(Crystal::ASTNode+)'

                  numeric_value = visitor.interpret_enum_value(value)
                                          ^~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:503: instantiating 'interpret_enum_value(Crystal::ASTNode+, Nil)'

  def interpret_enum_value(node : ASTNode, target_type = nil)
  ^

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:505: instantiating 'Crystal::MathInterpreter#interpret(Crystal::ASTNode+, Nil)'

    interpreter.interpret(node, target_type)
                ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/math_interpreter.cr:34: instantiating 'interpret_call_macro?(Crystal::Call, Nil)'

        value = interpret_call_macro?(node, target_type)
                ^~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/math_interpreter.cr:101: instantiating 'Crystal::SemanticVisitor+#expand_macro(Crystal::Call)'

    if visitor.expand_macro(node, raise_on_missing_const: false, first_pass: true)
               ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:257: instantiating 'eval_macro(Crystal::Call)'

      eval_macro(node) do
      ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:257: instantiating 'eval_macro(Crystal::Call)'

      eval_macro(node) do
      ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:258: instantiating 'Crystal::ASTNode+#accept(Crystal::SemanticVisitor+)'

        expanded.accept self
                 ^~~~~~

in /usr/lib/crystal/compiler/crystal/syntax/visitor.cr:27: instantiating 'Crystal::SemanticVisitor+#visit(Crystal::ASTNode+)'

        if visitor.visit self
                   ^~~~~

in /usr/lib/crystal/compiler/crystal/semantic/type_declaration_visitor.cr:52: instantiating 'super(Crystal::Include)'

      super
      ^~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:119: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

    node.hook_expansions.try &.each &.accept self
                         ^~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:119: instantiating '(Array(Crystal::ASTNode) | Nil)#try()'

    node.hook_expansions.try &.each &.accept self
                         ^~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:119: instantiating 'Array(Crystal::ASTNode)#each()'

    node.hook_expansions.try &.each &.accept self
                               ^~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/indexable.cr:187: instantiating 'each_index()'

    each_index do |i|
    ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:119: instantiating 'Array(Crystal::ASTNode)#each()'

    node.hook_expansions.try &.each &.accept self
                               ^~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:119: instantiating 'Crystal::ASTNode+#accept(Crystal::TypeDeclarationVisitor)'

    node.hook_expansions.try &.each &.accept self
                                      ^~~~~~

in /usr/lib/crystal/compiler/crystal/syntax/visitor.cr:27: instantiating 'Crystal::TypeDeclarationVisitor#visit(Crystal::ASTNode+)'

        if visitor.visit self
                   ^~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:157: instantiating 'expand_macro(Crystal::Call)'

    !expand_macro(node, raise_on_missing_const: false)
     ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:254: instantiating 'expand_macro(Crystal::Call, Bool, Bool)'

  def expand_macro(node, raise_on_missing_const = true, first_pass = false)
  ^

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:293: instantiating 'expand_macro_arguments(Crystal::Call, Crystal::Type+)'

    args = expand_macro_arguments(node, expansion_scope)
           ^~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:365: instantiating 'Crystal::MacroExpression#accept(Crystal::TypeDeclarationVisitor)'

          arg.accept self
              ^~~~~~

in /usr/lib/crystal/compiler/crystal/syntax/visitor.cr:27: instantiating 'Crystal::TypeDeclarationVisitor#visit(Crystal::MacroExpression)'

        if visitor.visit self
                   ^~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:161: instantiating 'expand_inline_macro(Crystal::MacroExpression)'

    expand_inline_macro node
    ^~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:386: instantiating 'expand_inline_macro(Crystal::MacroExpression, Nil)'

  def expand_inline_macro(node, mode = nil)
  ^

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:398: instantiating 'expand_macro(Crystal::Macro, Crystal::MacroExpression)'

    generated_nodes = expand_macro(the_macro, node, mode: mode) do
                      ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:314: instantiating 'eval_macro(Crystal::MacroExpression)'

      eval_macro(node) do
      ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:314: instantiating 'eval_macro(Crystal::MacroExpression)'

      eval_macro(node) do
      ^~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:398: instantiating 'expand_macro(Crystal::Macro, Crystal::MacroExpression)'

    generated_nodes = expand_macro(the_macro, node, mode: mode) do
                      ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/semantic/semantic_visitor.cr:400: instantiating 'Crystal::Program#expand_macro(Crystal::MacroExpression, Crystal::Type+, (Crystal::Type | Nil), Nil, (Crystal::Def | Nil))'

        @program.expand_macro node, (@scope || current_type), @path_lookup, free_vars, @untyped_def
                 ^~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/macros/macros.cr:48: instantiating 'Crystal::MacroExpression#accept(Crystal::MacroInterpreter)'

    node.accept interpreter
         ^~~~~~

in /usr/lib/crystal/compiler/crystal/syntax/visitor.cr:27: instantiating 'Crystal::MacroInterpreter#visit(Crystal::MacroExpression)'

        if visitor.visit self
                   ^~~~~

in /usr/lib/crystal/compiler/crystal/macros/interpreter.cr:100: instantiating 'Crystal::ASTNode+#accept(Crystal::MacroInterpreter)'

      node.exp.accept self
               ^~~~~~

in /usr/lib/crystal/compiler/crystal/syntax/visitor.cr:27: instantiating 'Crystal::MacroInterpreter#visit(Crystal::ASTNode+)'

        if visitor.visit self
                   ^~~~~

in /usr/lib/crystal/compiler/crystal/macros/interpreter.cr:152: instantiating 'interpret_top_level_call?(Crystal::Call)'

      if value = interpret_top_level_call?(Call.new(nil, node.name))
                 ^~~~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/macros/methods.cr:71: instantiating 'interpret_run(Crystal::Call)'

        interpret_run(node)
        ^~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/macros/methods.cr:239: instantiating 'Crystal::Program#macro_run(String, Array(String))'

      result = @program.macro_run(filename, run_args)
                        ^~~~~~~~~

in /usr/lib/crystal/compiler/crystal/macros/macros.cr:94: instantiating 'macro_compile(String)'

    compiled_macro_run = @compiled_macros_cache[filename] ||= macro_compile(filename)
                                                              ^~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/macros/macros.cr:150: instantiating 'Crystal::Compiler#compile(Crystal::Compiler::Source, String)'

    result = compiler.compile Compiler::Source.new(filename, source), executable_path
                      ^~~~~~~

in /usr/lib/crystal/compiler/crystal/compiler.cr:164: instantiating 'new_program(Array(Crystal::Compiler::Source))'

      program = new_program(source)
                ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/compiler.cr:199: instantiating 'Crystal::Program.class#new()'

      program = Program.new
                        ^~~

in /usr/lib/crystal/compiler/crystal/program.cr:243: instantiating 'define_crystal_constants()'

      define_crystal_constants
      ^~~~~~~~~~~~~~~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/program.cr:270: instantiating 'Crystal::Config:Module#description()'

      define_crystal_string_constant "DESCRIPTION", Crystal::Config.description
                                                                    ^~~~~~~~~~~

in /usr/lib/crystal/compiler/crystal/config.cr:18: instantiating 'version()'

        Crystal #{version} #{formatted_sha}(#{date})
                  ^~~~~~~

in /usr/lib/crystal/compiler/crystal/config.cr:8: expanding macro

      {{ read_file("#{__DIR__}/../../../VERSION").chomp }}
      ^

in /usr/lib/crystal/compiler/crystal/config.cr:8: Error opening file '/usr/lib/crystal/compiler/crystal/../../../VERSION' with mode 'r': No such file or directory

      {{ read_file("#{__DIR__}/../../../VERSION").chomp }}
         ^~~~~~~~~