$ sudo gem install libarchive

ERROR:  Error installing libarchive:
    ERROR: Failed to build gem native extension.

        /usr/bin/ruby1.9.1 extconf.rb
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking for special C compiler options needed for large files... no
checking for _FILE_OFFSET_BITS value needed for large files... no
checking for a BSD-compatible install... /usr/bin/install -c
configure: creating ./config.status
config.status: creating config.h
checking for config.h... yes
checking for archive.h... yes
checking for archive_entry.h... yes
checking for zlib.h... yes
checking for bzlib.h... yes
creating Makefile

make
compiling archive_write_open_rb_str.c
compiling archive_read_support_compression.c
archive_read_support_compression.c:8:3: warning: ‘archive_read_support_compression_none’ is deprecated (declared at /usr/include/archive.h:323) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_NONE,     archive_read_support_compression_none     },
   ^
archive_read_support_compression.c:9:3: warning: ‘archive_read_support_compression_gzip’ is deprecated (declared at /usr/include/archive.h:317) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_GZIP,     archive_read_support_compression_gzip     },
   ^
archive_read_support_compression.c:10:3: warning: ‘archive_read_support_compression_bzip2’ is deprecated (declared at /usr/include/archive.h:313) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_BZIP2,    archive_read_support_compression_bzip2    },
   ^
archive_read_support_compression.c:11:3: warning: ‘archive_read_support_compression_compress’ is deprecated (declared at /usr/include/archive.h:315) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_COMPRESS, archive_read_support_compression_compress },
   ^
compiling libarchive.c
In file included from libarchive_internal.h:31:0,
                 from libarchive.c:1:
/usr/include/ruby-1.9.1/ruby/backward/rubysig.h:14:2: warning: #warning rubysig.h is obsolete [-Wcpp]
 #warning rubysig.h is obsolete
  ^
libarchive.c: In function ‘rb_libarchive_s_version_number’:
libarchive.c:11:3: warning: implicit declaration of function ‘archive_version_stamp’ [-Wimplicit-function-declaration]
   return INT2NUM(archive_version_stamp());
   ^
compiling libarchive_writer.c
In file included from libarchive_internal.h:31:0,
                 from libarchive_writer.c:1:
/usr/include/ruby-1.9.1/ruby/backward/rubysig.h:14:2: warning: #warning rubysig.h is obsolete [-Wcpp]
 #warning rubysig.h is obsolete
  ^
libarchive_writer.c: In function ‘rb_libarchive_writer_close0’:
libarchive_writer.c:10:3: warning: ‘archive_write_finish’ is deprecated (declared at /usr/include/archive.h:721) [-Wdeprecated-declarations]
   archive_write_finish(p->ar);
   ^
libarchive_writer.c: In function ‘rb_libarchive_writer_s_open0’:
libarchive_writer.c:35:5: warning: ‘archive_write_set_compression_program’ is deprecated (declared at /usr/include/archive.h:630) [-Wdeprecated-declarations]
     r = archive_write_set_compression_program(p->ar,  cmd);
     ^
compiling libarchive_entry.c
In file included from libarchive_internal.h:31:0,
                 from libarchive_entry.c:1:
/usr/include/ruby-1.9.1/ruby/backward/rubysig.h:14:2: warning: #warning rubysig.h is obsolete [-Wcpp]
 #warning rubysig.h is obsolete
  ^
libarchive_entry.c: In function ‘rb_libarchive_entry_fflags’:
libarchive_entry.c:209:3: warning: pointer targets in passing argument 2 of ‘archive_entry_fflags’ differ in signedness [-Wpointer-sign]
   archive_entry_fflags(p->ae, &set, &clear);
   ^
In file included from libarchive_internal.h:28:0,
                 from libarchive_entry.c:1:
/usr/include/archive_entry.h:205:18: note: expected ‘long unsigned int *’ but argument is of type ‘long int *’
 __LA_DECL void   archive_entry_fflags(struct archive_entry *,
                  ^
libarchive_entry.c:209:3: warning: pointer targets in passing argument 3 of ‘archive_entry_fflags’ differ in signedness [-Wpointer-sign]
   archive_entry_fflags(p->ae, &set, &clear);
   ^
In file included from libarchive_internal.h:28:0,
                 from libarchive_entry.c:1:
/usr/include/archive_entry.h:205:18: note: expected ‘long unsigned int *’ but argument is of type ‘long int *’
 __LA_DECL void   archive_entry_fflags(struct archive_entry *,
                  ^
libarchive_entry.c: In function ‘rb_libarchive_entry_copy_stat’:
libarchive_entry.c:832:5: warning: spurious trailing ‘%’ in format [-Wformat=]
     rb_raise(rb_eArchiveError, "Copy stat failed: %", strerror(errno));
     ^
libarchive_entry.c:832:5: warning: too many arguments for format [-Wformat-extra-args]
libarchive_entry.c: In function ‘rb_libarchive_entry_copy_lstat’:
libarchive_entry.c:850:5: warning: spurious trailing ‘%’ in format [-Wformat=]
     rb_raise(rb_eArchiveError, "Copy stat failed: %", strerror(errno));
     ^
libarchive_entry.c:850:5: warning: too many arguments for format [-Wformat-extra-args]
compiling archive_write_set_compression.c
archive_write_set_compression.c:8:3: warning: ‘archive_write_set_compression_none’ is deprecated (declared at /usr/include/archive.h:628) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_NONE,     archive_write_set_compression_none     },
   ^
archive_write_set_compression.c:9:3: warning: ‘archive_write_set_compression_gzip’ is deprecated (declared at /usr/include/archive.h:622) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_GZIP,     archive_write_set_compression_gzip     },
   ^
archive_write_set_compression.c:10:3: warning: ‘archive_write_set_compression_bzip2’ is deprecated (declared at /usr/include/archive.h:618) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_BZIP2,    archive_write_set_compression_bzip2    },
   ^
archive_write_set_compression.c:12:3: warning: ‘archive_write_set_compression_compress’ is deprecated (declared at /usr/include/archive.h:620) [-Wdeprecated-declarations]
   { ARCHIVE_COMPRESSION_COMPRESS, archive_write_set_compression_compress },
   ^
compiling archive_read_support_format.c
compiling libarchive_archive.c
In file included from libarchive_internal.h:31:0,
                 from libarchive_archive.c:1:
/usr/include/ruby-1.9.1/ruby/backward/rubysig.h:14:2: warning: #warning rubysig.h is obsolete [-Wcpp]
 #warning rubysig.h is obsolete
  ^
libarchive_archive.c: In function ‘rb_libarchive_archive_position_compressed’:
libarchive_archive.c:28:3: warning: ‘archive_position_compressed’ is deprecated (declared at /usr/include/archive.h:900) [-Wdeprecated-declarations]
   return LONG2NUM(archive_position_compressed(p->ar));
   ^
libarchive_archive.c: In function ‘rb_libarchive_archive_position_uncompressed’:
libarchive_archive.c:36:3: warning: ‘archive_position_uncompressed’ is deprecated (declared at /usr/include/archive.h:903) [-Wdeprecated-declarations]
   return LONG2NUM(archive_position_uncompressed(p->ar));
   ^
libarchive_archive.c: In function ‘rb_libarchive_archive_compression_name’:
libarchive_archive.c:44:3: warning: ‘archive_compression_name’ is deprecated (declared at /usr/include/archive.h:906) [-Wdeprecated-declarations]
   return rb_str_new2(archive_compression_name(p->ar));
   ^
libarchive_archive.c:44:3: warning: ‘archive_compression_name’ is deprecated (declared at /usr/include/archive.h:906) [-Wdeprecated-declarations]
libarchive_archive.c:44:3: warning: ‘archive_compression_name’ is deprecated (declared at /usr/include/archive.h:906) [-Wdeprecated-declarations]
libarchive_archive.c:44:3: warning: ‘archive_compression_name’ is deprecated (declared at /usr/include/archive.h:906) [-Wdeprecated-declarations]
libarchive_archive.c: In function ‘rb_libarchive_archive_compression’:
libarchive_archive.c:52:3: warning: ‘archive_compression’ is deprecated (declared at /usr/include/archive.h:909) [-Wdeprecated-declarations]
   return INT2NUM(archive_compression(p->ar));
   ^
compiling libarchive_reader.c
In file included from libarchive_internal.h:31:0,
                 from libarchive_reader.c:1:
/usr/include/ruby-1.9.1/ruby/backward/rubysig.h:14:2: warning: #warning rubysig.h is obsolete [-Wcpp]
 #warning rubysig.h is obsolete
  ^
libarchive_reader.c: In function ‘rb_libarchive_reader_close0’:
libarchive_reader.c:10:3: warning: ‘archive_read_finish’ is deprecated (declared at /usr/include/archive.h:585) [-Wdeprecated-declarations]
   archive_read_finish(p->ar);
   ^
libarchive_reader.c: In function ‘rb_libarchive_reader_s_open0’:
libarchive_reader.c:35:5: warning: ‘archive_read_support_compression_program’ is deprecated (declared at /usr/include/archive.h:325) [-Wdeprecated-declarations]
     r = archive_read_support_compression_program(p->ar, cmd);
     ^
libarchive_reader.c:39:5: warning: ‘archive_read_support_compression_all’ is deprecated (declared at /usr/include/archive.h:311) [-Wdeprecated-declarations]
     r = archive_read_support_compression_all(p->ar);
     ^
libarchive_reader.c: In function ‘rb_libarchive_reader_s_open_filename0’:
libarchive_reader.c:92:7: error: format not a string literal and no format arguments [-Werror=format-security]
       archive_set_error(p->ar, -1, strerror(errno));
       ^
libarchive_reader.c: In function ‘rb_libarchive_reader_save_data’:
libarchive_reader.c:275:3: warning: implicit declaration of function ‘_close’ [-Wimplicit-function-declaration]
   _close(fd);
   ^
cc1: some warnings being treated as errors
make: *** [libarchive_reader.o] Error 1


Gem files will remain installed in /var/lib/gems/1.9.1/gems/libarchive-0.1.2 for inspection.
Results logged to /var/lib/gems/1.9.1/gems/libarchive-0.1.2/ext/gem_make.out