When configuring Qt the second time it might be situation that the set of qt_find_package calls is changed. One of the scenarios is the changing of the submodule list that needs to be built in top-level builds. It's also applicable for Qt features that lead to extra package lookup in the unlocked subdirectories. Current approach collects packages that were found at the previous run and skips search of the packages that are missing. The problem is that it also skips packages even if qt_find_package was not called at previous run. QT_INTERNAL_PREVIOUSLY_SEARCHED_PACKAGES collects all packages that were actually searched at the previous run to make sure that qt_find_package don't skip packages that appeared at second run only. Note: Described scenarios may still have other issues and are not tested well. Fixes: QTBUG-113244 Pick-to: 6.5 Change-Id: Iab36060a28fbaa16a3b3bdba67795955c496b0c3 Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io> Reviewed-by: Amir Masoud Abdol <amir.abdol@qt.io>