Warn when combining Qt 5.12 with older Qt

Fixes #4581

1 files changed, 9 insertions, 1 deletions

diff --git a/qutebrowser/misc/earlyinit.py b/qutebrowser/misc/earlyinit.py
index a2db81764..61ae1dbfc 100644
--- a/qutebrowser/misc/earlyinit.py
+++ b/qutebrowser/misc/earlyinit.py
@@ -173,8 +173,10 @@ def check_qt_version():
                               PYQT_VERSION_STR)
     from pkg_resources import parse_version
     from qutebrowser.utils import log
+    parsed_qversion = parse_version(qVersion())
+
     if (QT_VERSION < 0x050701 or PYQT_VERSION < 0x050700 or
-            parse_version(qVersion()) < parse_version('5.7.1')):
+            parsed_qversion < parse_version('5.7.1')):
         text = ("Fatal error: Qt >= 5.7.1 and PyQt >= 5.7 are required, "
                 "but Qt {} / PyQt {} is installed.".format(qt_version(),
                                                            PYQT_VERSION_STR))
@@ -184,6 +186,12 @@ def check_qt_version():
         log.init.warning("Running qutebrowser with Qt 5.8 is untested and "
                          "unsupported!")
 
+    if (parsed_qversion >= parse_version('5.12') and
+            (PYQT_VERSION < 0x050c00 or QT_VERSION < 0x050c00)):
+        log.init.warning("Combining PyQt {} with Qt {} is unsupported! Ensure "
+                         "all versions are newer than 5.12 to avoid potential "
+                         "issues.".format(PYQT_VERSION_STR, qt_version()))
+
 
 def check_ssl_support():
     """Check if SSL support is available."""