C:\> gem install redis-dump --platform=ruby
Temporarily enhancing PATH to include DevKit...
Building native extensions.  This could take a while...
ERROR:  Error installing redis-dump:
        ERROR: Failed to build gem native extension.

    C:/Ruby21/bin/ruby.exe extconf.rb
creating Makefile

make "DESTDIR=" clean

make "DESTDIR="
generating yajl-i386-mingw32.def
compiling yajl.c
yajl.c: In function 'yajl_status_to_string':
yajl.c:61:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_alloc':
yajl.c:105:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_reset_parser':
yajl.c:110:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_free':
yajl.c:119:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_parse':
yajl.c:128:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_parse_complete':
yajl.c:140:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_get_error':
yajl.c:147:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_get_bytes_consumed':
yajl.c:154:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
yajl.c: In function 'yajl_free_error':
yajl.c:162:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes]
compiling yajl_alloc.c
yajl_alloc.c: In function 'yajl_set_default_alloc_funcs':
yajl_alloc.c:64:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribut
compiling yajl_buf.c
yajl_buf.c: In function 'yajl_buf_alloc':
yajl_buf.c:78:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes
yajl_buf.c: In function 'yajl_buf_free':
yajl_buf.c:85:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes
yajl_buf.c: In function 'yajl_buf_append':
yajl_buf.c:96:1: warning: visibility attribute not supported in this configuration; ignored [-Wattributes
yajl_buf.c: In function 'yajl_buf_clear':
yajl_buf.c:102:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribute
yajl_buf.c: In function 'yajl_buf_data':
yajl_buf.c:107:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribute
yajl_buf.c: In function 'yajl_buf_len':
yajl_buf.c:112:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribute
yajl_buf.c: In function 'yajl_buf_truncate':
yajl_buf.c:119:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribute
compiling yajl_encode.c
yajl_encode.c: In function 'yajl_string_encode2':
yajl_encode.c:99:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribu
yajl_encode.c: In function 'yajl_string_encode':
yajl_encode.c:52:1: warning: visibility attribute not supported in this configuration; ignored [-Wattribu
yajl_encode.c: In function 'yajl_string_decode':
yajl_encode.c:201:1: warning: visibility attribute not supported in this configuration; ignored [-Wattrib
compiling yajl_ext.c
In file included from c:/Ruby21/include/ruby-2.1.0/ruby.h:33:0,
                 from yajl_ext.h:32,
                 from yajl_ext.c:24:
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:109:14: error: size of array 'ruby_check_sizeof_voidp' is negati
In file included from c:/Ruby21/include/ruby-2.1.0/ruby.h:33:0,
                 from yajl_ext.h:32,
                 from yajl_ext.c:24:
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h: In function 'rb_obj_wb_unprotect':
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1234:9: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1235:6: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1238:2: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h: In function 'rb_obj_written':
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1253:9: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h: In function 'rb_num2char_inline':
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1324:35: warning: cast to pointer from integer of different size
ter-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1324:35: warning: cast to pointer from integer of different size
ter-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1324:35: warning: cast to pointer from integer of different size
ter-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1325:9: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1325:9: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1325:9: warning: cast to pointer from integer of different size
er-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h: In function 'rb_class_of':
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1642:12: warning: cast to pointer from integer of different size
ter-cast]
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h: In function 'rb_type':
c:/Ruby21/include/ruby-2.1.0/ruby/ruby.h:1659:12: warning: cast to pointer from integer of different size
ter-cast]
yajl_ext.c: In function 'yajl_check_and_fire_callback':
yajl_ext.c:38:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:38:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:38:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:42:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:42:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:42:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:47:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:47:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:47:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_set_static_value':
yajl_ext.c:81:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:81:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:81:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:83:11: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:83:11: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:83:11: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_encode_part':
yajl_ext.c:168:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:168:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:168:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:181:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:181:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:181:28: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:200:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:200:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:200:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:201:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:201:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:201:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:208:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:208:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:208:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:209:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:209:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:209:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:216:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:216:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:216:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:217:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:217:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:217:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:222:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:222:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:222:24: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:223:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:223:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:223:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_found_hash_key':
yajl_ext.c:313:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:313:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:313:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_found_start_hash':
yajl_ext.c:342:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:342:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:342:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_found_end_hash':
yajl_ext.c:350:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:350:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:350:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:352:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:352:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:352:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_found_start_array':
yajl_ext.c:361:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:361:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:361:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'yajl_found_end_array':
yajl_ext.c:369:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:369:5: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
yajl_ext.c:369:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:371:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:371:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:371:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'rb_yajl_parser_new':
yajl_ext.c:423:58: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'rb_yajl_parser_parse':
yajl_ext.c:477:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:491:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:491:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:491:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:492:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:492:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:492:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:497:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:497:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:497:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:498:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:498:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:498:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:509:38: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:471:17: warning: variable '_stat64' set but not used [-Wunused-but-set-variable]
yajl_ext.c: In function 'rb_yajl_parser_parse_chunk':
yajl_ext.c:531:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:537:29: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:537:29: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:537:29: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:538:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:538:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:538:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'rb_yajl_parser_set_complete_cb':
yajl_ext.c:558:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'rb_yajl_encoder_new':
yajl_ext.c:606:56: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:606:56: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:606:56: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:607:38: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:607:38: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:607:38: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:607:59: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:607:59: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:607:59: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:608:30: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:608:30: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c:608:30: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'rb_yajl_encoder_encode':
yajl_ext.c:680:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
yajl_ext.c: In function 'rb_yajl_encoder_set_progress_cb':
yajl_ext.c:732:5: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
make: *** [yajl_ext.o] Error 1

make failed, exit code 2

Gem files will remain installed in C:/Ruby21/lib/ruby/gems/2.1.0/gems/yajl-ruby-1.2.1 for inspection.
Results logged to C:/Ruby21/lib/ruby/gems/2.1.0/extensions/x86-mingw32/2.1.0/yajl-ruby-1.2.1/gem_make.out