cannot load such file -- mysql2/mysql2 (LoadError)
While upgrading to Rails 4, lot of gem dependencies change as expected
To keep the dependencies clean, we decided to create a new gemset in rvm to install everything fresh and ensuring no existing dependencies / gems preventing us from any surprise on SERVER deploy
What you get different in a new gemset is that all other gems installed long time back and working are installed again and all the linking / dependency resolution is done again which might throw a surprise.
Why new rvm gemset
It might not be relevant / seen futile by developers already working on project as everything is installed and working for them but is highly critical for NEW developers who would join or to install on new machines too for existing developers
Everything starts with de-facto
bundle install
And here come’s the surprise
mysql2 gem failed to install
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/Users/pikender/.rvm/rubies/ruby-2.0.0-p451/bin/ruby extconf.rb
checking for ruby/thread.h... yes
checking for rb_thread_call_without_gvl() in ruby/thread.h... yes
checking for rb_thread_blocking_region()... yes
checking for rb_wait_for_single_fd()... yes
checking for rb_hash_dup()... yes
checking for rb_intern3()... yes
-----
Using mysql_config at /usr/local/mysql/bin/mysql_config
-----
checking for mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
-----
Setting rpath to /usr/local/mysql/lib
-----
creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
compiling client.c
compiling infile.c
compiling mysql2_ext.c
compiling result.c
linking shared-object mysql2/mysql2.bundle
couldn't understand kern.osversion `14.5.0'
ld: warning: directory not found for option
'-L/Users/travis/.sm/pkg/active/lib'
ld: -rpath can only be used when targeting Mac OS X 10.5 or later
collect2: ld returned 1 exit status
make: *** [mysql2.bundle] Error 1
make failed, exit code 2
Gem files will remain installed in
/Users/pikender/.rvm/gems/ruby-2.0.0-p451@easyerrands/gems/mysql2-0.3.20
for inspection.
Results logged to
/Users/pikender/.rvm/gems/ruby-2.0.0-p451@easyerrands/extensions/x86_64-darwin-12/2.0.0-static/mysql2-0.3.20/gem_make.out
An error occurred while installing mysql2 (0.3.20), and Bundler cannot
continue.
Make sure that `gem install mysql2 -v '0.3.20'` succeeds before
bundling.
Solution 1
export MACOSX_DEPLOYMENT_TARGET=10.5
Then bundle install and application will run smoothly :)
Solution 2
After a little bit of search came across below solution and mysql2 gem install worked
gem install mysql2 -v '0.3.13' -- --srcdir=/usr/local/mysql/include
Happy and resumed bundle install. It finished smoothly.
Fired the Rails Server bundle exec rails s
Boom !!!
Below Error shown in backtrace
/usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `require': cannot load such file -- mysql2/mysql2 (LoadError)
Browsing through stackoverflow and mention of above errors, landed on mysql2 issue and couldn’t understand kern.osversion `14.0.0’
With the help of pointers in above references, fixed it by editing
Makefile to use CC as /usr/bin/gcc instead of
/usr/local/bin/gcc-4.2
Its always better to install new projects under different rvm gemsets
to better know / handle adaptation to changes in OS due to upgrades or
otherwise.
References
- https://github.com/brianmario/mysql2/issues/192#issuecomment-22910390
- http://stackoverflow.com/questions/28068383/why-does-homebrew-report-couldnt-understand-kern-osversion-14-0-0