Where do the pkg-config targets get defined?

Question

When I perform the command

pkg-config --variable pc_path pkg-config

The output is

/usr/lib64/pkgconfig:/usr/share/pkgconfig

However, there are two other pkgconfig directories on my system: /usr/lib/pkgconfig and /usr/local/lib/pkgconfig

If I try

echo $PKG_CONFIG_PATH

the result is

Undefined variable

I also tried to

export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig

but the response was

export: Command not found.

Now, I have built Gstreamer on multiple occasions and it will put the metadata files (gstreamer-1.0.pc) into the other pkgconfig folder (usr/local/lib/pkgconfig). (I have been able to overcome this issue by modifying the configure file, changing lib to lib64 at the libdir definition.) But I would rather understand my system rather than try work-arounds.

So two questions: where does the pkg-config program get its target directories?

And why and how do the metadata files get put into a directory that is not apparently indicated by the pkg-config program?

Thanks to @Grisha Levit for editing my poorly presented question. Neither of the answers given actually answers my two questions although l appreciate the effort to get me a solution. — jackson80

Mausam Sinha Mausam Sinha · Accepted Answer · 2017-02-11T04:02:07

Since the command is not working because that variable was not present first check that variable is there or not for to do this execute command env root@localhost:/etc/apt# env if the path is not declare in env then do something like

root@localhost:/etc/apt# PKG_CONFIG_PATH=/usr/local/lib/pkgconfig root@localhost:/etc/apt# export PKG_CONFIG_PATH root@localhost:/etc/apt# echo $PKG_CONFIG_PATH /usr/local/lib/pkgconfig root@localhost:/etc/apt# env

Hope this will work for you for any further help please post the queries with error

Where do the pkg-config targets get defined?

2 Answers