Installing gems with extensions always fails

Question

I just setup an Ubuntu 13.04 server, and installed RVM 1.21.11, Ruby 1.9.3-p448, and Rubygems 2.0.5 .

Many gems, such as mongo, awesome_print, aws-s3, and json, installed successfully.

However, gems that compile an extension fail. I've tried to install nokogiri, mongo_ext, and bson_ext . They all fail in the same way, as shown below.

Any idea how to fix this?

[nick@mongo01 ~] gem install mongo_ext -u -V --backtrace
HEAD http://rubygems.org/latest_specs.4.8.gz
302 Moved Temporarily
HEAD http://production.s3.rubygems.org/latest_specs.4.8.gz
304 Not Modified
Installing gem mongo_ext-0.19.3
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/Rakefile
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/mongo-extensions.gemspec
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/extconf.rb
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/buffer.c
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/cbson.c
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/encoding_helpers.c
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/buffer.h
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/encoding_helpers.h
/usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/version.h
Building native extensions.  This could take a while...
/usr/local/rvm/rubies/ruby-1.9.3-p448/bin/ruby extconf.rb
checking for asprintf()... yes
checking for ruby/st.h... yes
checking for ruby/regex.h... yes
checking for ruby/encoding.h... yes
creating Makefile
make "DESTDIR="
compiling encoding_helpers.c
compiling buffer.c
compiling cbson.c
cbson.c: In function 'write_utf8':
cbson.c:80:36: warning: pointer targets in passing argument 1 of 'check_string' differ in signedness [-Wpointer-sign]
In file included from cbson.c:46:0:
encoding_helpers.h:26:10: note: expected 'const unsigned char *' but argument is of type 'char *'
cbson.c: In function 'objectid_generate':
cbson.c:858:5: warning: implicit declaration of function 'htonl' [-Wimplicit-function-declaration]
cbson.c:867:5: warning: implicit declaration of function 'htons' [-Wimplicit-function-declaration]
cbson.c: In function 'write_element':
cbson.c:264:17: warning: ignoring return value of 'asprintf', declared with attribute warn_unused_result [-Wunused-result]
linking shared-object mongo_ext/cbson.so
make "DESTDIR=" install
/usr/bin/install -c -m 0755 cbson.so /usr/local/rvm/gems/ruby-1.9.3-p448/gems/mongo_ext-0.19.3/ext/cbson/.gem.20130718-9545-1ue92ws/mongo_ext
installing default cbson libraries
ERROR:  While executing gem ... (NoMethodError)
    undefined method `join' for nil:NilClass
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/installer.rb:685:in `rescue in block in build_extensions'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/installer.rb:675:in `block in build_extensions'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/installer.rb:653:in `each'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/installer.rb:653:in `build_extensions'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/installer.rb:218:in `install'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/dependency_installer.rb:371:in `block in install'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/dependency_installer.rb:331:in `each'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/dependency_installer.rb:331:in `each_with_index'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/dependency_installer.rb:331:in `install'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/commands/install_command.rb:166:in `block in execute'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/commands/install_command.rb:158:in `each'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/commands/install_command.rb:158:in `execute'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/command.rb:305:in `invoke_with_build_args'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/command_manager.rb:170:in `process_args'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/command_manager.rb:130:in `run'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/lib/ruby/site_ruby/1.9.1/rubygems/gem_runner.rb:60:in `run'
        /usr/local/rvm/rubies/ruby-1.9.3-p448/bin/gem:21:in `<main>'
[nick@mongo01 ~]
[nick@mongo01 ~] gem -v
2.0.5
[nick@mongo01 ~] ruby -v
ruby 1.9.3p448 (2013-06-27 revision 41675) [x86_64-linux]
[nick@mongo01 ~] rvm -v

rvm 1.21.11 (stable) by Wayne E. Seguin <[e-mail]>, Michal Papis <[e-mail]> [https://rvm.io/]

Answer 1

This was caused by a bug in RubyGems. It was fixed in 8d1751c6.

Until RubyGems v2.0.6 is released, a workaround is to apply 8d1751c6 manually.

Answer 2

This is often because the native extension needs to be compiled on your system, and you don't have the proper development tools installed. Have you done this?

 yum groupinstall 'Development Tools'

Perhaps one of these tools is the wrong version, or otherwise hosed?