One of the gem I use is mysql. It used to work. I still have forensic evidence of that in the older place where gems were installed (deep within /Library/Frameworks).

Now it doesn't install. Here is the full terminal transcript:

Building native extensions.  This could take a while...

ERROR:  Error installing mysql:

ERROR: Failed to build gem native extension.

        /Library/Frameworks/MacRuby.framework/Versions/0.12/usr/bin/macruby extconf.rb

checking for mysql_ssl_set()... yes

checking for rb_str_set_len()... yes

checking for rb_thread_start_timer()... no

checking for mysql.h... yes

i686-apple-darwin11-llvm-gcc-4.2: conftest.m: No such file or directory

i686-apple-darwin11-llvm-gcc-4.2: no input files

*** 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=/Library/Frameworks/MacRuby.framework/Versions/0.12/usr/bin/macruby

--with-mysql-config

--without-mysql-config

/Library/Frameworks/MacRuby.framework/Versions/0.12/usr/lib/ruby/1.9.2/mkmf.rb:1987:in `mkmf_failed': *** 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=/Library/Frameworks/MacRuby.framework/Versions/0.12/usr/bin/macruby

--with-mysql-config

--without-mysql-config

 (SystemExit)

from /Library/Frameworks/MacRuby.framework/Versions/0.12/usr/lib/ruby/1.9.2/mkmf.rb:2077:in `block'

from /Library/Ruby/Gems/MacRuby/0.12/gems/mysql-2.8.1/ext/mysql_api/extconf.rb:75:in `<main>'

Gem files will remain installed in /Library/Ruby/Gems/MacRuby/0.12/gems/mysql-2.8.1 for inspection.

Results logged to /Library/Ruby/Gems/MacRuby/0.12/gems/mysql-2.8.1/ext/mysql_api/gem_make.out

I checked the mkmf.log for more info. Here is its full content:

have_func: checking for mysql_ssl_set()... -------------------- yes

"/usr/bin/gcc-4.2 -o conftest -I/Library/Frameworks/MacRuby.framework/Versions/0.12/usr/include/ruby-1.9.2/universal-darwin10.0 -I/Library/Frameworks/MacRuby.framework/Versions/0.12/usr/include/ruby-1.9.2/ruby/backward -I/Library/Frameworks/MacRuby.framework/Versions/0.12/usr/include/ruby-1.9.2 -I.  -I/opt/local/include/mysql5/mysql  -pipe -fPIC    -D_P1003_1B_VISIBLE -DSIGNAL_WITH_VIO_CLOSE -DSIGNALS_DONT_BREAK_READ -DIGNORE_SIGHUP_SIGQUIT  -DDONT_DECLARE_CXA_PURE_VIRTUAL -fobjc-gc-only -arch x86_64 -fexceptions -fno-common -pipe -O3 -g -Wall -fobjc-gc--------------------

I tried to execute the call to gcc-4.2 in there. gcc replies "no input files".

the mkmf.rb file mentioned is a MacRuby file and the gem installs fine using the regular "gem" command, so I suspect the problem is MacRuby's (especially since I had installed no so long ago), but I am not enough of a rubyist to go further.

Any suggestion?

Thanks,

Jean-Denis