Where does Qt-Creator get the "System Environment" from?

[hackdev]

Hi there,

I would like to add the the pkg-config installation directory to the PATH, and I want to set the PKG_CONFIG_PATH variable. However, I don't want to do it on a project basis. I want to do it only once for all projects.

I understand that Qt-Creator doesn't use the bash environment, and nor does it uses anything set in .profile, /etc/paths, or /etc/paths.d.

There used to be a solution for this. That is, to use the ~/.MacOSX/environment.plist as stated here https://forum.qt.io/topic/5716/qt-creator-doesn-t-recognize-path-variable-on-mac-osx/2, but this doesn't seem to work on osx yosemite.

Some people claim that putting it in a startup file like ~/Library/LaunchAgents/my.startup.plist works, as stated here http://apple.stackexchange.com/questions/106355/setting-the-system-wide-path-environment-variable-in-mavericks, but I couldn't get it to work.

Hence my question: where does Qt-Creator get the "System Environment" from? Because I would like to modify that source directly. Furthermore, is it possible to do this from the .pro file? That is, is it possible to do something like PATH += ${PATH}:x/y/z in a .pro file, and alter the Build environment? That would be even more convenient.

Thank you.