编译ZeroMQ以支持Libsodium出现的“ No package 'libsodium' found”问题

在编译zeromq以支持libsodium时出现找不到libsodium包问题：checking for sodium... no执行"./configure --prefix=/usr --with-libsodium"出现：

[root@localhost zeromq-4.1.2]#./configure --prefix=/usr --with-libsodium

checking for sodium... no

configure: error: Package requirements (libsodium) were not met:

No package 'libsodium' found

Consider adjusting the PKG_CONFIG_PATH environment variable if you

installed software in a non-standard prefix.

Alternatively, you may set the environment variables sodium_CFLAGS

and sodium_LIBS to avoid the need to call pkg-config.

根据提示：查看PKG_CONFIG_PATH环境变量，

echo $PKG_CONFIG_PATH

此时问空，原来如此。

加上pkg-config路径即可

export PKG_CONFIG_PATH=/usr/lib/pkgconfig

此时再次./configure就通过。