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

在macOS(以前的Mac OS X和OS X)上,使用Homebrew安装正确的头文件:

brew install postgresql

然后运行

gem install pg

应该工作。

或者,不安装整个postgresql,你可以酿造安装libpq并导出正确的PATH和PKG_CONFIG_PATH,如“警告”部分所述

其他回答

看起来在Ubuntu中,头文件是libpq-dev包的一部分(至少在以下Ubuntu版本中是这样的: 11.04 (Natty Narwhal), 10.04 (Lucid Lynx), 11.10 (Oneiric Ocelot), 12.04 (Precise穿山甲),14.04 (Trusty Tahr)和18.04(仿生海狸)):

...
/usr/include/postgresql/libpq-fe.h
...

所以试着为你的操作系统安装libpq-dev或类似的软件:

Ubuntu/Debian系统:sudo apt-get install libpq-dev RHEL系统:yum install postgresql-devel 对于Mac Homebrew: brew安装postgresql 对于Mac MacPorts PostgreSQL: gem install pg -- --with-pg-config=/opt/local/lib/ PostgreSQL[版本号]/bin/pg_config . exe OpenSuse:在postgresql-devel中使用zypper 对于ArchLinux: pacman -S postgresql-libs

在Arch Linux上,你需要安装postgresql-libs:

sudo pacman -Syu postgresql-libs

我通过rvm重新安装Ruby修复了同样的错误:

rvm reinstall 1.9.3

我找到了这个答案,这是唯一一个对我有用的(Mac OS)——在研究了大约两天之后:

$ sudo su

$ env ARCHFLAGS="-arch x86_64" gem install pg

Building native extensions.  This could take a while...
Successfully installed pg-0.11.0
1 gem installed
Installing ri documentation for pg-0.11.0...
Installing RDoc documentation for pg-0.11.0...

参见堆栈溢出问题无法找到PostgreSQL客户端库(libpq)。

我最近升级到Mac OS X v10.10 (Yosemite),在构建pg gem时遇到了困难。

报告的错误是典型的:

Using config values from /usr/local/bin/pg_config
checking for libpq-fe.h... *** extconf.rb failed ***

我的解决方案是卸载pg gem,然后捆绑更新pg,用最新的gem替换gem。我确实运行了brew update;在Yosemite安装后进行brew升级,以获得我之前安装的软件包的最新版本。