Rails: Installing PG gem on OS X - failure to build native extension

Question

It seems many others have had problems installing the pg gem. None of the solutions posed for others have worked for me.

I have tried to install the pg gem and postgres.app. The pg gem won't install. The first error I get is:

An error occurred while installing pg (0.17.0), and Bundler cannot continue. Make sure that gem install pg -v '0.17.0' succeeds before bundling.

The installation advice about pointing my gem install to the config for pg fails with the following error message (which many others on this forum have encountered):

Failed to build native extensions... Results logged to /Users/melanie/.rvm/gems/ruby-1.9.3-p448/gems/pg-0.17.0/ext/gem_make.out

I don't know how to find or access this log file to search for further clues.

I also get an error message (command not found) when I try using the sudo apt-get install command. I've scoured this forum for the last 6 hours, trying each piece of advice to get pg working with my rails project.

I can't find advice about how to change a path, or specifically, what change is required. My which pg_config returns a file source. I've used that with a command to install pg using that config. It fails.

There are so many people that have had trouble with this. Many answers suggest homebrew. I've had to remove that because it threw up other issues.

Answer 1

For AWS EC2 (Amazon Linux) user:

# This 3 lines are used to `gem install pg ...` successfully
yum install ruby-devel
yum groupinstall "Development Tools"
yum install postgresql-devel # After you run this, you will have a `/usr/bin/pg_config` to be used
gem install pg -v '1.5.6' -- --with-pg-config=/usr/bin/pg_config

Answer 2

i got same problem and i solved

gem update --system 3.0.6

Answer 3

running brew update and then brew install postgresql worked for me, I was able to run the pg gem file no problem after that.

Answer 4

For those who are not interested to use brew.

1. Download PostgreSQL application.
2. Follow the macOS default instruction to install it.
3. It is advisable to run PostgreSQl.
4. Run gem install pg -- --with-pg-config=/path/to/postgress/in/your/applications/folder/`
   • For example, in my machine it is /Applications/Postgres.app/Contents/Versions/12/bin/pg_config

Answer 5

Solved! I found some lack of library for PostgreSQL on the system. Only two steps solved it:

brew install postgresql

Then run

gem install pg

Answer 6

On OSX with Postgres installed in /Applications, I simply run the following command (change 0.20 & 9.4 according to your version)

gem install pg -v '0.20' -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config

You should have :

Building native extensions with: '--with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config' This could take a while... Successfully installed pg-0.20.

Answer 7

Same error for me and I didn't experience it until I downloaded OS X 10.9 (Mavericks). Sigh, another OS upgrade headache.

Here's how I fixed it (with homebrew):

• Install another build of Xcode Tools (typing brew update in the terminal will prompt you to update the Xcode build tools)
• brew update
• brew install postgresql

After that gem install pg worked for me.

Answer 8

I believe the “correct” answer would be to first configure PATH correctly for Postgres.app by adding the following to ~/.profile (.zshrc or ~/.zprofile if using ZSH):

export PATH=$PATH:/Applications/Postgres.app/Contents/Versions/latest/bin

Then open a new tab or window in terminal and install the pg gem with:

ARCHFLAGS="-arch x86_64" gem install pg

Documented here:

• https://postgresapp.com/documentation/cli-tools.html
• https://postgresapp.com/documentation/configuration-ruby.html

Answer 9

easy step

1. brew install postgresql
2. gem install pg -v 'your version'

Answer 10

I spent a day on this and here's how I got it fixed:

I found that global value of build.pg was set to: /opt/local/lib/postgresql91/bin/pg_config and that was not where postgres was installed.

I fixed it with replacing the value of build.pg to: bundle config build.pg --with-pg-config=/usr/local/Cellar/postgresql/9.4.4/bin/pg_config which is where my postgresql installation is.

Answer 11

Try:

gem install pg -- --with-pg-config=`which pg_config`

Answer 12

I tried everything for hours but the following finally fixed it (I'm on OS X 10.9.4):

1. Install Xcode command line tools (Apple Developer site)
2. brew uninstall postgresql
3. brew install postgresql
4. ARCHFLAGS="-arch x86_64" gem install pg

Answer 13

If you are using Ubuntu try to install following lib file

sudo apt-get install libpq-dev

and then

gem install pg

worked for me.

Answer 14

Ok I also had this problem (psql is v 9.3.0 and ruby is v 2.1.2) and the solution that worked for me was setting the bundle config settings first:

bundle config build.pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.3/bin/pg_config

This answer finally helped me figure it out: https://stackoverflow.com/a/9235107/3546680

Answer 15

Similarly, after installing Mavericks bundle update was throwing an error on the pg gem, which is only used on production and not locally.

I use Brew to manage my packages and postgresql was already installed, but still I was getting the 'no pg_config' error.

The fix was to just brew uninstall postgresql, then brew install postgresql. After which I was immediately able to successfully run bundle update.

Answer 16

I am using OS X Mavericks (version 10.9)

and when I run the above I got the following message: If builds of PostgreSQL 9 are failing and you have version 8.x installed.

So I run the following command:

ARCHFLAGS="-arch x86_64" gem install pg

and this worked for me, I hope this helps someone :)