我使用的是Ruby on Rails 3.1预版本。我喜欢使用PostgreSQL,但问题是安装pg gem。它给了我以下错误:

$ gem install pg
Building native extensions.  This could take a while...
ERROR:  Error installing pg:
    ERROR: Failed to build gem native extension.

        /home/u/.rvm/rubies/ruby-1.9.2-p0/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.

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=/home/u/.rvm/rubies/ruby-1.9.2-p0/bin/ruby
    --with-pg
    --without-pg
    --with-pg-dir
    --without-pg-dir
    --with-pg-include
    --without-pg-include=${pg-dir}/include
    --with-pg-lib
    --without-pg-lib=${pg-dir}/lib
    --with-pg-config
    --without-pg-config
    --with-pg_config
    --without-pg_config
    Gem files will remain installed in /home/u/.rvm/gems/ruby-1.9.2-p0/gems/pg-0.11.0 for inspection.
    Results logged to /home/u/.rvm/gems/ruby-1.9.2-p0/gems/pg-0.11.0/ext/gem_make.out

我怎么解决这个问题?


当前回答

只是缺少libpq-fe.h的问题

在ubuntu上,我们只需要运行: Sudo apt-get安装libpq-dev

上面的命令将安装一个新的包libpq-dev,之后你可以再次执行bundle install来继续你的包安装。

其他回答

找不到libpq-fe.h头文件

我在CentOS 7.0.1406上运行以下命令成功:

~ % psql --version # => psql (PostgreSQL) 9.4.1
yum install libpqxx-devel
gem install pg -- --with-pg-config=/usr/pgsql-9.4/bin/pg_config

或者,你可以配置捆绑器总是安装pg,使用这些选项(有助于在部署环境中运行捆绑器),

包配置构建。pg - with-pg-config = / usr / bin / pg_config / pgsql - 9.4

在OS X和MacPorts上,PostgreSQL不再需要-devel包。安装pg gem的步骤如下:

~ > sudo port install postgresql-devel
...
Error: postgresql-devel has been replaced by postgresql91; please install that port instead
~ > gem install pg -v '0.17.1' -- --with-pg-config=/opt/local/lib/postgresql95/bin/pg_config

参见这篇文章。

在FreeBSD(9.1)上,必要的包是/usr/ports/database/postgresql-server*,安装时也会安装所需的头文件,使gem安装“pg”失败。这里的答案帮助我找到解决方案,但包名的差异需要进行一些搜索。

希望这能帮助人们在FreeBSD系统上搜索“-dev”包时避免一点挠头!

我在Mac OS上也有同样的问题,但我在终端上使用以下方法轻松安装了PostgreSQL gem:

ARCHFLAGS="-arch x86_64" gem install pg

(我先用brew install PostgreSQL安装PostgreSQL。)

我也尝试过做gem安装libpq-dev,但我收到了这个错误:

Can't find the 'libpq-fe.h header
*** extconf.rb failed ***

然而,我发现使用sudo apt-get(我尽量避免在Ruby on Rails中使用)安装是有效的,即。

sudo apt-get install libpq-dev
# or
apt-get install postgres-server-dev-{pg.version}
# for postgresql 9.4 on Ubuntu 14.04

然后我就能做了

gem install pg

没有问题。