How to automatically rebuild a precompiled header using qmake when its dependencies change?

Question

I'm using qmake's PRECOMPILED_HEADER variable to generate a precompiled header.

If one of the precompiled header's included headers changes, the precompiled header isn't rebuilt — instead, when clang tries to use the precompiled header, it fails with fatal error: file '...' has been modified since the precompiled header was built.

How can I tell qmake to automatically recompile the precompiled header when its dependencies change?

Answer 1

My problem was that I had CONFIG -= depend_includepath enabled, and I had added the precompiled header's headers to INCLUDEPATH but hadn't also added them to DEPENDPATH.

Answer 2

Edit prefix header anyhow. E.g if your precompiled header created from stdafx.h, open stdafx.h and type something, than delete it, save file and launch build again.