我在升级到Mountain Lion后，Rails出现了很多问题。
为了解决这些问题，我在网上搜索了数小时，并采取了以下措施，以确保我的系统在升级后具备运行Rails的所有依赖项：
- I updated my Homebrew installation
- I updated my RVM installation
- I installed the XCode command line tools
- I installed GCC as mentioned
- I upgraded my version of Ruby to
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]
- My Rails version is verified as Rails 3.2.6
I also found out that Mountain Lion has some issues with Postgres so I saw this post and found out that I need to add this line to my Bash profile:
export PATH="/usr/local/bin:/usr/bin:$PATH"
现在我要去我的Rails应用程序，以前在Snow Leopard上运行得很好，但在我升级后，当我在命令行中运行rails s时，我会收到以下错误：
AM@~/Documents/RailsWS/app0815 >gem install pg
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
/Users/AM/.rvm/rubies/ruby-1.9.2-p290/bin/ruby extconf.rb
checking for pg_config... yes
Using config values from /usr/bin/pg_config
checking for libpq-fe.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/Users/AM/.rvm/rubies/ruby-1.9.2-p290/bin/ruby
--with-pg
--without-pg
--with-pg-dir
--without-pg-dir
--with-pg-include
--without-pg-include=${pg-dir}/include
--with-pg-lib
--without-pg-lib=${pg-dir}/lib
--with-pg-config
--without-pg-config
--with-pg_config
--without-pg_config
/Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:368:in `try_do':
The complier failed to generate an executable file. (RuntimeError)
You have to install development tools first.
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:452:in `try_cpp'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:853:in `block in find_header'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:693:in `block in checking_for'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:280:in `block (2 levels) in postpone'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:280:in `block in postpone'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:276:in `postpone'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:692:in `checking_for'
from /Users/AM/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/mkmf.rb:852:in `find_header'
from extconf.rb:41:in `<main>'
Gem files will remain installed in /Users/AM/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.14.1 for inspection.
Results logged to /Users/AM/.rvm/gems/ruby-1.9.2-p290/gems/pg-0.14.1/ext/gem_make.out
当我进入Rails应用并尝试运行
bundle install时，pg安装失败。