I am pretty sure this problem started only since I upgraded OS to El-Capitan. Tried running
sudo gem install -n /usr/local/bin compass
And I am getting the error
ERROR: Error installing compass:
ERROR: Failed to build gem native extension.
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby -r ./siteconf20160413-36157-1bn6ytd.rb extconf.rb
checking for ffi.h... /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:434:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:549:in `block in try_compile'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:502:in `with_werror'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:549:in `try_compile'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:1038:in `block in have_header'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:889:in `block in checking_for'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:340:in `block (2 levels) in postpone'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:310:in `open'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:340:in `block in postpone'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:310:in `open'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:336:in `postpone'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:888:in `checking_for'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/mkmf.rb:1037:in `have_header'
from extconf.rb:16:in `<main>'
extconf failed, exit code 1
Gem files will remain installed in /Library/Ruby/Gems/2.0.0/gems/ffi-1.9.6 for inspection.
Results logged to /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-15/2.0.0/ffi-1.9.6/gem_make.out
Xcode is already installed so I have no idea what the problem is. Any help would be appreciated. Thanks!
Related
error Ignoring ffi-1.15.5 because its extensions are not built. Try: gem pristine ffi --version 1.15.5
Ignoring io-console-0.6.0 because its extensions are not built. Try: gem pristine io-console --version 0.6.0
Ignoring json-2.6.3 because its extensions are not built. Try: gem pristine json --version 2.6.3
Ignoring openssl-3.1.0 because its extensions are not built. Try: gem pristine openssl --version 3.1.0
Ignoring psych-5.1.0 because its extensions are not built. Try: gem pristine psych --version 5.1.0
Ignoring racc-1.6.2 because its extensions are not built. Try: gem pristine racc --version 1.6.2
Ignoring readline-ext-0.1.5 because its extensions are not built. Try: gem pristine readline-ext --version 0.1.5
Ignoring stringio-3.0.5 because its extensions are not built. Try: gem pristine stringio --version 3.0.5
Ignoring strscan-3.0.5 because its extensions are not built. Try: gem pristine strscan --version 3.0.5
Ignoring zlib-3.0.0 because its extensions are not built. Try: gem pristine zlib --version 3.0.0
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in require': incompatible library version - /Users/admin/.rvm/gems/ruby-2.7.5/gems/zlib-3.0.0/lib/zlib.bundle (LoadError) from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/fetcher.rb:6:in <top (required)>' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in require' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/cli/install.rb:53:in run'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/cli.rb:235:in block in install' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/settings.rb:143:in temporary'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/cli.rb:234:in install' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/vendor/thor/lib/thor/command.rb:27:in run'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/vendor/thor/lib/thor/invocation.rb:126:in invoke_command' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/vendor/thor/lib/thor.rb:387:in dispatch'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/cli.rb:27:in dispatch' from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/vendor/thor/lib/thor/base.rb:466:in start'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/cli.rb:18:in start' from /Library/Ruby/Gems/2.6.0/gems/bundler-1.17.2/exe/bundle:30:in block in <top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/friendly_errors.rb:124:in with_friendly_errors' from /Library/Ruby/Gems/2.6.0/gems/bundler-1.17.2/exe/bundle:22:in <top (required)>'
from /usr/local/bin/bundle:23:in load' from /usr/local/bin/bundle:23:in '
✖ Installing Bundler
error Error: Looks like your iOS environment is not properly set. Please go to https://reactnative.dev/docs/next/environment-setup and follow the React Native CLI QuickStart guide for macOS and iOS.
Error: Error: Looks like your iOS environment is not properly set. Please go to https://reactnative.dev/docs/next/environment-setup and follow the React Native CLI QuickStart guide for macOS and iOS.
at createFromTemplate (/Users/admin/node_modules/#react-native-community/cli/build/commands/init/init.js:129:11)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async Object.initialize [as func] (/Users/admin/node_modules/#react-native-community/cli/build/commands/init/init.js:181:3)
at async Command.handleAction (/Users/admin/node_modules/#react-native-community/cli/build/index.js:106:9)
info Run CLI with --verbose flag for more details.
initiating react-native project .
I tried to add the unicorn gem to my gem file and when I run bundle install I get the following error:
Installing kgio (2.8.1) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby extconf.rb
checking for CLOCK_MONOTONIC in time.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby
/usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:381:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:491:in `block in try_compile'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:443:in `with_werror'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:491:in `try_compile'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:686:in `macro_defined?'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:822:in `block in have_macro'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
from /usr/local/rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/mkmf.rb:821:in `have_macro'
from extconf.rb:5:in `<main>'
Gem files will remain installed in /usr/local/rvm/gems/ruby-1.9.3-p392/gems/kgio-2.8.1 for inspection.
Results logged to /usr/local/rvm/gems/ruby-1.9.3-p392/gems/kgio-2.8.1/ext/kgio/gem_make.out
An error occurred while installing kgio (2.8.1), and Bundler cannot continue.
Make sure that `gem install kgio -v '2.8.1'` succeeds before bundling.
Prior to including the unicorn gem I have no problems running bundle install. It appears to be failing while trying to install kgio 2.8.1. I've searched for solutions on Stackoverflow and elsewhere, the most common solution appears to be to install the Xcode development tools. I've done this and it has not resolved the issue.
I'm running Mac OSX 10.9.1 Mavericks with Ruby 1.9.3p392. Really need to get this resolved, any help would be very much appreciated.
I updated to Ruby 2.1 and the problem was resolved.
The problem:
I have this gem that I am working on. While trying to install it locally to do some tests, rake install fails after building the gem. Rake suggested that I run gem install for the built gem to debug. Surprisingly, gem install pkg/my_gem-x.y.z.gem works like a charm!
Any idea why?
Some details:
rake version: 10.0.3
Gem created using bundler version: 1.2.1
Contents of gemspec:
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'my_gem/version'
Gem::Specification.new do |gem|
gem.name = "mygem"
gem.version = MyGem::VERSION
gem.authors = ["Omar Abdel-Wahab"]
gem.email = ["me#example.com"]
gem.description = %q{bla bla bla}
gem.summary = %q{bla bla bla}
gem.homepage = "http://github.com/foobar/"
gem.files = `git ls-files`.split($/)
gem.executables = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
gem.test_files = gem.files.grep(%r{^(test|spec|features)/})
gem.require_paths = ["lib"]
gem.add_dependency "rails", ">= 3.1"
gem.add_dependency "jquery-rails"
gem.add_dependency "twitter-bootstrap-rails", ">= 2.1.0"
gem.add_development_dependency "bundler", ">= 1.0.0"
gem.add_development_dependency "rspec", "~> 2.3"
gem.add_development_dependency "sqlite3-ruby"
end
Output from rake install:
~/Projects/Github/my_gem% rake -vt install
** Invoke install (first_time)
** Execute install
my_gem 0.0.1 built to pkg/my_gem-0.0.1.gem
rake aborted!
Couldn't install gem, run `gem install /Users/owahab/Projects/Github/my_gem/pkg/my_gem-0.0.1.gem' for more detailed output
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:68:in `install_gem'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/bundler-1.2.1/lib/bundler/gem_helper.rb:43:in `block in install'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:228:in `call'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:228:in `block in execute'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:223:in `each'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:223:in `execute'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:166:in `block in invoke_with_call_chain'
/Users/owahab/.rvm/rubies/ruby-1.9.3-p286/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:159:in `invoke_with_call_chain'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/task.rb:152:in `invoke'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:143:in `invoke_task'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:101:in `each'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:101:in `block in top_level'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:110:in `run_with_threads'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:95:in `top_level'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:73:in `block in run'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/rake-10.0.3/bin/rake:33:in `<top (required)>'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/rake:19:in `load'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/rake:19:in `<main>'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/ruby_noexec_wrapper:14:in `eval'
/Users/owahab/.rvm/gems/ruby-1.9.3-p286/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => install
Output from rake build then gem install:
~/Projects/Github/rails_autocomplete% rake build && gem install pkg/my_gem-0.0.1.gem
my_gem 0.0.1 built to pkg/my_gem-0.0.1.gem
Successfully installed my_gem-0.0.1
1 gem installed
Installing ri documentation for my_gem-0.0.1...
Building YARD (yri) index for my_gem-0.0.1...
Installing RDoc documentation for my_gem-0.0.1...
Based on the comment thread on the question, it was a permission problem. Debugging Bundler's gem_helper.rb file revealed this:
ERROR: While executing gem ... (Errno::EACCES) Permission denied - /Users/owahab/.rvm/gems/ruby-1.9.3-p286/gems/i18n-0.6.1/ci/Gemfile.no-rails
Some gems had been installed as root. Removing them solved the problem.
I began by installing all these dependencies:
sudo yum install ruby19 ruby19-devel gem rubygems19-devel make gcc postgresql9 postgresql9-devel postgresql9-server
Then I switch to the root user and I run
bundle install
and I get the green success message:
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.
However, when I cd to the dir and run
rails s -p80
it I get all this and it fails to start (I'm still root because bind won't work to port 80 if I'm not root):
/usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require': cannot load such file -- pg_ext (LoadError)
from /usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `block in require'
from /usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:236:in `load_dependency'
from /usr/local/share/gems/gems/activesupport-3.2.8/lib/active_support/dependencies.rb:251:in `require'
from /usr/local/share/gems/gems/pg-0.14.0/lib/pg.rb:4:in `<top (required)>'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:68:in `require'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:66:in `each'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:66:in `block in require'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:55:in `each'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler/runtime.rb:55:in `require'
from /usr/local/share/gems/gems/bundler-1.2.0/lib/bundler.rb:128:in `require'
from /home/user/TransForm/config/application.rb:7:in `<top (required)>'
from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:53:in `require'
from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:53:in `block in <top (required)>'
from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:50:in `tap'
from /usr/local/share/gems/gems/railties-3.2.8/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
Perhaps there is an easy way to just deploy it correctly from the begining instead of messing around with error craps? I need PostgreSQL. This app works everywhere except this AWS EC2 instance, so I know my Gemfile is correct. Any clues would help.
open irb & type require "pg" does it work? if not, then check that pg_ext exists in /usr/local/share/gems/gems/pg-0.14.0/lib/ directory. you can install manually postgresql gem manually, using
gem install pg
If this still doesn't work, ensure that you are using latest version of ruby & latest version of rubygems using gem environment command.if its the older version, you can install latest ones using rvm
use gem pg
than
bundle install
bundle update
please not use any version of pg
I face this error and solved by this
I created a new rails project calling
rails new simple_cms
Then when in the directory I run
rails s
I get the follow errors
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-x86-mingw32/l
ib/mysql2/mysql2.rb:2:in `require': Incorrect MySQL client library version! This
gem was compiled for 6.0.0 but the client library is 5.5.24. (RuntimeError)
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-
x86-mingw32/lib/mysql2/mysql2.rb:2:in `<top (required)>'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-
x86-mingw32/lib/mysql2.rb:9:in `require'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.11-
x86-mingw32/lib/mysql2.rb:9:in `<top (required)>'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler/runtime.rb:68:in `require'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler/runtime.rb:68:in `block (2 levels) in require'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler/runtime.rb:66:in `each'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler/runtime.rb:66:in `block in require'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler/runtime.rb:55:in `each'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler/runtime.rb:55:in `require'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/bundler-1.1.3/
lib/bundler.rb:119:in `require'
from c:/development/ruby/simple_cms/config/application.rb:7:in `<top (re
quired)>'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/commands.rb:53:in `require'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/commands.rb:53:in `block in <top (required)>'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/commands.rb:50:in `tap'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-3.2.3
/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
I have seen other people with this error but they tend to be linux users and I am running windows. I have attempted to reinstall both rails (railsinstaller.org) and mysql 5.5. I have used both the 32bit version as well as the 64bit version
There seem to be several questions on here already about this. Did you try their solutions?
Probably the most clear is this:
mysql2 gem compiled for wrong mysql client library
The pertinent part is here:
At the time of building this gem, the necessary DLL files where available
in the following download:
http://dev.mysql.com/get/Downloads/Connector-C/mysql-connector-c-noinstall-6.0.2-win32.zip/from/pick
And put lib\libmysql.dll file in your Ruby bin directory, for example
C:\Ruby\bin
This will remove the gem and its dependencies. Then reinstalling will re-compile itself and all dependencies.
gem uninstall mysql2
bundle install
I had this error in a new project I was working on which suddenly stopped working in a windows machine that already had working rails projects, so it was clearly not an installation problem.
What caused the problem was a bundle update command, which decided to redownload mysql2 gem (for unknown reasons) and ignored my Gemfile line gem 'mysql2', '~> 0.2.6'.
The problem was that bundle update got mysql version 0.2.18, as shown in Gemfile.lock, in the following line:
mysql2 (0.2.18-x86-mingw32)
I'm note sure what the symbol means, but I replaced the following line in my gemfile
gem 'mysql2', '~> 0.2.6'
for
gem 'mysql2', '0.2.6'
And now everything works fine, including bundle update.