没有 postgresql 捆绑安装失败

Question

当我运行 bundle install 时，我收到此错误：

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

current directory: /usr/local/lib/ruby/gems/2.3.0/gems/pg-0.18.4/ext
/usr/local/opt/ruby/bin/ruby -r ./siteconf20160601-64492-1nt86nq.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.

... [a long list of config options] ...

An error occurred while installing pg (0.18.4), and Bundler cannot continue.
Make sure that `gem install pg -v '0.18.4'` succeeds before bundling.

然后，当我尝试 gem install pg -v '0.18.4' 时，就像它所暗示的那样，我得到了同样的错误，而没有建议运行我刚刚尝试过的命令。我没有运行 postgres，也从未安装过它，所以我对为什么会发生这种情况有点困惑。

这里有一个类似的问题，但同样，我没有 postgresql。我需要吗？问题：gem install pg -v 0.12.2 error on mac

感谢任何帮助。谢谢你。

Answer 1

是的，要安装 pg gem，您必须安装 postgresql。您可以在their website找到下载和安装说明。

特别是它说你需要一个pg_config 文件，我猜它会在安装时创建。