--- a/mercurial/utils/procutil.py	Tue Feb 02 23:44:44 2021 +0530
+++ b/mercurial/utils/procutil.py	Thu Feb 04 19:56:45 2021 +0900
@@ -546,7 +546,11 @@
             # pure build; use a safe default
             return True
     else:
-        return pycompat.iswindows or encoding.environ.get(b"DISPLAY")
+        return (
+            pycompat.iswindows
+            or encoding.environ.get(b"DISPLAY")
+            or encoding.environ.get(b"WAYLAND_DISPLAY")
+        )
 
 
 def gui():