The documentation of QProcess is insonsistent. I was searching for setting the environment in the method list at top and could not find anything. With Chrome search I could find a reference on page later. However, it is not marked as a proper reference.

systemEnvironment can be found under static methods. There is a reference to setEnvironment, but it links to an obsolete page.

see also post and subsequent http://forum.qt.io/topic/52585/qprocess-documentation-is-inconsistent/2