configure: show the logs of check_qml_module.py in the logs

So we know what is failing.

buildsystem/check_qml_module.py

@@ -54,6 +54,7 @@ class QmlModuleChecker:
             )
 
         if ret.returncode != 0:
+            print(ret.stderr.strip())
             return None
 
         return json.loads(ret.stdout)
@@ -89,7 +90,8 @@ class QmlModuleChecker:
         )
 
         if ret.returncode != 0:
-            return None
+            print(ret.stderr.strip())
+            return False
 
         binpath = None
         libexec = None
@@ -111,7 +113,7 @@ class QmlModuleChecker:
             self.qt5 = False
 
         if not checkQmakePath(self.qmlpath):
-            print("Qml path not found")
+            print("Qml path {} not found".format(self.qmlpath))
             return False
 
         self.qmlimportscanner = findProgram(binpath, "qmlimportscanner")

configure.ac

@@ -4089,7 +4089,8 @@ AS_IF([test "${enable_qt}" != "no"], [
             QtQuick.Layouts="" \
             QtQuick.Window="" \
             QtQuick.Controls="" \
-            Qt5Compat.GraphicalEffects=""], [
+            Qt5Compat.GraphicalEffects="" \
+            >&AS_MESSAGE_FD ], [
         AC_MSG_RESULT([yes])
       ],[
         AC_MSG_RESULT([no])
@@ -4101,7 +4102,8 @@ AS_IF([test "${enable_qt}" != "no"], [
           AS_IF([test "$PYTHON3" != "no" && ${PYTHON3} ${srcdir}/buildsystem/check_qml_module.py \
             --qmake "${QMAKE}" \
             --qtconf "${CONTRIB_DIR}/bin/target_qt.conf" \
-            --modules QtTest=""], [
+            --modules QtTest="" \
+            >&AS_MESSAGE_FD ], [
               have_qt_quick_test="yes"
           ], [])
       ],[