Error seen during "gem install pg"
Installing pg 0.18.3 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
/Users/jmatthews/.rvm/rubies/ruby-2.2.2/bin/ruby -r ./siteconf20160219-13102-1ygzen8.rb 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.
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=/Users/jmatthews/.rvm/rubies/ruby-2.2.2/bin/$(RUBY_BASE_NAME)
--with-pg
--without-pg
--enable-windows-cross
--disable-windows-cross
--with-pg-config
--without-pg-config
--with-pg_config
--without-pg_config
--with-pg-dir
--without-pg-dir
--with-pg-include
--without-pg-include=${pg-dir}/include
--with-pg-lib
--without-pg-lib=${pg-dir}/lib
extconf failed, exit code 1
Gem files will remain installed in /Users/jmatthews/.rvm/gems/ruby-2.2.2/gems/pg-0.18.3 for inspection.
Results logged to /Users/jmatthews/.rvm/gems/ruby-2.2.2/extensions/x86_64-darwin-14/2.2.0-static/pg-0.18.3/gem_make.out
Solution
$ gem install pg -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config
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-0.18.4
Parsing documentation for pg-0.18.4
Installing ri documentation for pg-0.18.4
Done installing documentation for pg after 3 seconds
1 gem installed
With Bundler
bundle config build.pg --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config
bundle install