gem install pg doesn't work on OSX Lion

Question

There are variations of this question bouncing around SO, but none of them seem to have an answer that solves my problem.

I am running OSX Lion (10.7.3). The latest

Answer 1

On OS X Mavericks

sudo ln -s /usr/bin/llvm-gcc /usr/bin/gcc-4.2

works.

Answer 2

I also ran into this issue, for me the answer was updating RVM of all things.

rvm get head
rvm install 1.9.2

Answer 3

I am on Mountain Lion, and the accepted answer from Dave Isaacs worked for me. I also had to do

sudo ln -s llvm-g++-4.2 g++-4.2

Answer 4

After a Mavericks upgrade...

Reinstall your ruby version.

rvm uninstall 1.9.2-p320

then

rvm install 1.9.2-p320

or whatever version of ruby you have.

Answer 5

I too, am on Mountain Lion, besides the "sudo ln -s /usr/bin/{llvm-,}gcc-4.2" suggested by @grilix, I needed to do:

sudo ln -s /usr/bin/{llvm-,}g++-4.2

Answer 6

$ gem install pg

If that failed:

$ sudo gem install pg

Then, if that failed:

$ sudo find / -name “pg_config”

After you find pg_config's location, run this to finally install it:

$ sudo gem install pg --with-pg-config=/usr/local/Cellar/postgresql/9.5.1/bin/pg_config

Of course, you'll want to change the path to wherever you found pg_config.

Then, check your installed gems with gem list, and it should show something like this:

More information can be found in my guide.