Previously .prl files were created via add_custom_command with a POST_BUILD command. This means they were only created after linking the libraries, and that whenever a relinking happened, dependees had to rebuild many parts of their target. Ideally we would use generator expressions in the OUTPUT argument, but versions up-to CMake 3.18 don't support doing that. A workaround is to create and depend on a .prl file name without generator expressions, and as a side effect also create a .prl file that does use generator expressions, but don't specify it as an OUTPUT. This seems to work well, and improves the dependency tracking issue, at the cost of one more file copy per .prl file whenever it changes. Change-Id: I7dd99777fec5a08552503bdbafb6116f93ebe66b Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org> Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>