An error occurred while installing pg (0.17.1), an

问题:

I just installed Rails 4.0.2 and when creating a new app, in the bundle stage I get:

Installing pg (0.17.1) 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
/Users/Dee/.rvm/rubies/ruby-2.0.0-p247/bin/ruby extconf.rb 
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
--with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** 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.

How do I fix this?

回答1:

I'm on a Mac running Mavericks. My solution was to install Postgres.

And then in terminal install using homebrew with the configuration:

gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/latest/bin/pg_config

Note: This answer has been edited to use the latest symlink that is currently included in shipping versions of the Postgres app.

Previous versions suggested:

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

回答2:

Some kind of error resported here Installing PG gem on OS X - failure to build native extension

To install dependencies on Ubuntu try this:

sudo apt-get install libpq-dev

and this

gem install pg

回答3:

app root:

1. brew update
2. brew install postgres
3. gem install pg -- --with-pg-config=/usr/local/Cellar/postgresql/9.3.4/bin/pg_config
4. bundle install
5. ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents
6. launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
7. createuser -s -r postgres
8. rake db:create:all
9. rake db:migrate
10. rails s

NOTE: replace the version number in step 3 if needed.

回答4:

Previously working answer with older version

I installed under mac OSX Mavericks, having the postgres app (Version 9.2.2.0 ) from www.postgresapp.com installed. The underlying problem was simpy that the since postgres was installed via the app, the configuration file resides on a location which is not the default one when installing it without postgressapp. so we need to tell gem where to find this file by:

gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/MacOS/bin/pg_config

Hope it helps

回答5:

If gem install pg fails, try the following command:

env ARCHFLAGS="-arch x86_64" gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/MacOS/bin/pg_config

... from the PostgreSQL.app Documentation

回答6:

Looks like you do not have PostgreSQL installed. The pg gem requires some headers from PostgreSQL to compile native extension.

回答7:

I had to combine everything and use

sudo env ARCHFLAGS="-arch x86_64" gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config

回答8:

If you are using something other than Postgres in development and Postgres in production only, you can add the pg gem to your gemfile like so...

group :production do
  gem 'pg',             '0.17.1'
end

Then use bundle install --without production

回答9:

For CentOS users:

sudo yum install postgresql-devel

and

gem install pg

回答10:

After installing Postgres I had to run the following command

env ARCHFLAGS="-arch x86_64" gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.3/bin/pg_config

After this bundle install works great!

Hope it helps

回答11:

The way I managed to get past that error was:

• cd to app folder and then set the ruby version locally. I'm using ruby 2.1.2.

rbenv local 2.1.2

• instead of just running bundle install, install the gems in vendor/bundle

bundle install --path vendor/bundle

This did it for me.

回答12:

I needed to use sudo

sudo gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.5/bin/pg_config

回答13:

It works for me

rvm list gemsets
rvm use ruby-2.4.1
bundle

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