在Heroku中安装gem'pg'的问题-Rails

Question

我正在尝试在heroku的 OSX的Rails上安装ruby，为此我使用了本教程 。 它似乎在终端上安装正常，但是在完成之后

$rails new myapp --database=postgresql
cd myapp

我做了这个

rails generate controller welcome

并得到一个错误：

Could not find gem 'spring (>= 0) ruby' in the gems available on this machine. Run Could not find gem 'spring (>= 0) ruby' in the gems available on this machine. Run捆绑安装to install missing gems.

按照指示操​​作后，我得到了

'An error occurred while installing pg (0.17.1), and Bundler cannot continue.
Make sure that `gem install pg -v '0.17.1'` succeeds before bundling.'

接着...

ERROR:  Error installing pg:
    ERROR: Failed to build gem native extension.

        ...
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.

一个类似的SO问题说，通过更新XCode解决了该问题，但是我不认为这是我的问题。 如果还不很明显，那么我对终端或红宝石的经验还不是很丰富，所以我不确定如何解决这个问题。

编辑：

新的错误信息

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

    /Users/mahireusufzai/.rbenv/versions/2.1.1/bin/ruby extconf.rb 
checking for pg_config... yes
Using config values from /usr/local/bin/pg_config
*** 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.

...

/Users/mahireusufzai/.rbenv/versions/2.1.1/lib/ruby/2.1.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
    from /Users/mahireusufzai/.rbenv/versions/2.1.1/lib/ruby/2.1.0/mkmf.rb:541:in `try_link0'
    from /Users/mahireusufzai/.rbenv/versions/2.1.1/lib/ruby/2.1.0/mkmf.rb:556:in `try_link'
    from extconf.rb:39:in `<main>'

extconf failed, exit code 1

Gem files will remain installed in /Users/mahireusufzai/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/pg-0.17.1 for inspection.

Answer 1

您需要先安装postgresql开发库。 它抱怨libpq-fe.h丢失。

尝试按照以下帖子中的答案解决： Rails：安装pg gem时出错

Answer 2

尝试

yum install postgresql-devel

要么

brew install postgresql

然后gem install pg应该工作