Prerequisites:

Parent process does have LD_LIBRARY_PATH set. Create a QProcess and set its env to a set of variables that does not include LD_LIBRARY_PATH.

What happens:

LD_LIBRARY_PATH is silently added by QProcess::start(), because the parent process has it set and it is not set top empty string in the env.

What should happen:

No surprises and no LD_LIBRARY_PATH in the child process. I would expect that the environment I set for the QProcess is final and nothing is added to it by the library.

If this would break existing code, at the very least, this should be documented.

Details

Apparently, this was a convenience added by Qt 3. See:
http://manpages.ubuntu.com/manpages/natty/man3/qprocess.3qt.html

I see no mention of LD_LIBRARY_PATH being inherited from the parent process in the current documentation. The `convenience' stayed, the documentation got lost.