升级后的pg_config，ruby pg，postgresql 9.0问题，centos 5
在postgresql 8.1升级到9.0之后，我发现了库依赖的问题。 Postgresql工作正常（连接，查询）。
yum list postgresql* Installed Packages postgresql.i386 9.0.0-1PGDG.el5 installed postgresql-debuginfo.i386 9.0.0-1PGDG.el5 installed postgresql-devel.i386 9.0.0-1PGDG.el5 installed postgresql-libs.i386 9.0.0-1PGDG.el5 installed postgresql-odbcng.i386 0.90.101-2.el5 installed postgresql-plruby.i386 0.5.1-5.el5 installed postgresql-server.i386 9.0.0-1PGDG.el5 install 但当我试图为ruby安装’pg’时，我收到了
gem install pg Building native extensions. This could take a while... ERROR: Error installing pg: ERROR: Failed to build gem native extension. /usr/local/bin/ruby extconf.rb checking for pg_config... no 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.
在尝试使用另一个ruby-postgres驱动程序时，我得到了
yum install ruby-postgres ruby-postgres-0.7.1-5.el5.i386 from epel has depsolving problems --> Missing Dependency: libpq.so.4 is needed by package ruby-postgres-0.7.1-5.el5.i386 (epel)
和
locate libpq.so.4 /usr/lib/libpq.so.4 /usr/lib/libpq.so.4.1
还出口路径
LD_LIBRARY_PATH=/usr/pgsql-9.0/lib export LD_LIBRARY_PATH
用“require pg”（在8.1上工作）运行ruby脚本之后，我得到了：
/usr/local/lib/ruby/site_ruby/1.8/i686-linux/pg_ext.so: libpq.so.4: cannot open shared object file: No such file or directory - /usr/local/lib/ruby/site_ruby/1.8/i686-linux/pg_ext.so (LoadError) from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in `require' from /usr/local/lib/ruby/site_ruby/1.8/pg.rb:12 from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in `gem_original_require' from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in `require'
有什么建议可以做更多吗？
您可以添加到gem安装中的各种配置选项，例如-with-opt-dir ， – --with-pg-dir和--with-pg-config 。 看看这个邮件列表线程：
$ gem --version 1.3.7 $ ruby --version ruby 1.9.2p180（2011-02-18修订版30909）[x86_64-linux] $ cat / etc / redhat-release CentOS版本5.4（最终版） $ uname -m x86_64的 sudo yum list安装| grep postgre（看看你安装了什么） sudo yum list available | grep postgre（我失踪了postgresql-devel） sudo yum install postgresql-devel（我安装了） sudo gem install pg（这次没错！） $ gem list --local | grep pg 第（0.11.0）页
这看起来像pg配置文件位置错误，
gem install pg -- --with-pgsql-lib=/usr/pgsql-9.0/lib --with-pg-config=/usr/pgsql-9.1/bin/pg_config
解决它!!
gem install pg -- --with-pgsql-lib=/usr/pgsql-9.0/lib --with-pg-config=/usr/pgsql-9.1/bin/pg_config /usr/local/lib/ruby/1.9.1/yaml.rb:56:in `': It seems your ruby installation is missing psych (for YAML output). To eliminate this warning, please install libyaml and reinstall your ruby. Building native extensions. This could take a while... Successfully installed pg-0.14.0 1 gem installed Installing ri documentation for pg-0.14.0... Installing RDoc documentation for pg-0.14.0...
在Mac OSX 10.6.8上，使用Postgres 9的MacPorts安装，以下命令对我有用：
gem install pg -- --with-pgsql-lib=/opt/local/lib/postgresql90/lib --with-pg-config=/opt/local/lib/postgresql90/bin/pg_config
libpq.so.4来自PostgreSQL的旧版本; 9.0附带/usr/pgsql-9.0/lib/libpq.so.5
如果你有一个针对libpq.so.4构建的程序，那么该文件由compat-postgresql-libs包提供，你可能没有安装它们。 很多人使用“–force”删除它，因为否则很难安装新的RPM; 这是一个坏主意，但替代方案很复杂 。 如果您已经安装了该软件包，那么您应该找到一个/usr/lib/libpq.so.4 ，它可以使您现有的程序（最初为较旧的PostgreSQL编译）感到高兴。