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

对于未安装PostgreSQL服务器的MacOS:

brew install libpq
gem install pg -- --with-pg-config="/usr/local/Cellar/libpq/9.6.6/bin/pg_config"

其他回答

在Mac上,我用下面的代码解决了这个问题:

gem install pg -v '0.18.4' -- --with-pg-config=/Applications/Postgres.app/Contents/Versions/9.4/bin/pg_config

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。)

在我的情况下,它是包postgresql-server-dev-8.4(我使用的是Ubuntu 11.04 (Natty Narwhal), 64位)。

在Fedora 32上,我通过专门安装libpq5-devel解决了同样的问题。

如果你从官方存储库安装postgresql,你会有几个版本都不能解决这个问题,所以这真的是一个尝试它需要哪个版本的问题。

Ubuntu 20.04.1 LTS,这似乎对我有用:

sudo apt-get install ruby ruby-dev libpqxx-dev libpq-fe-dev libpq-dev 
sudo gem install pg -- --with-pg-config=/usr/include/postgresql/pg_config --with-pg-include=/usr/include/postgresql/