qmake: Emit warning when regenerating Xcode project during build

Makes it a bit more clear why all the Xcode settings were lost.

Task-number: QTBUG-45113
Change-Id: I3b19edb02a24673f56e77d3a1fb7cc76584c73fd
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 4 insertions, 0 deletions

diff --git a/qmake/generators/mac/pbuilder_pbx.cpp b/qmake/generators/mac/pbuilder_pbx.cpp
index 57a1bff3a0..d3ee8a24ea 100644
--- a/qmake/generators/mac/pbuilder_pbx.cpp
+++ b/qmake/generators/mac/pbuilder_pbx.cpp
@@ -542,6 +542,10 @@ ProjectBuilderMakefileGenerator::writeMakeParts(QTextStream &t)
             QTextStream mkt(&mkf);
             writeHeader(mkt);
             mkt << "QMAKE    = " << var("QMAKE_QMAKE") << endl;
+            project->values("QMAKE_MAKE_QMAKE_EXTRA_COMMANDS")
+                << "@echo 'warning: Xcode project has been regenerated, custom settings have been lost. " \
+                   "Use CONFIG+=no_autoqmake to prevent this behavior in the future, " \
+                   "at the cost of requiring manual project change tracking.'";
             writeMakeQmake(mkt);
             mkt.flush();
             mkf.close();