set QT_QPA_FONTDIR

Author: skvark

cv2/__init__.py

@@ -9,16 +9,25 @@
 # this makes them available
 globals().update(importlib.import_module("cv2.cv2").__dict__)
 
-is_ci_build = False
+ci_and_not_headless = False
 
 try:
-    from .version import ci_build
-    is_ci_build = ci_build
+    from .version import ci_build, headless
+
+    ci_and_not_headless = ci_build and not headless
 except:
     pass
 
 # the Qt plugin is included currently only in the pre-built wheels
-if (sys.platform == "darwin" or sys.platform.startswith("linux")) and is_ci_build:
+if (
+    sys.platform == "darwin" or sys.platform.startswith("linux")
+) and ci_and_not_headless:
     os.environ["QT_QPA_PLATFORM_PLUGIN_PATH"] = os.path.join(
         os.path.dirname(os.path.abspath(__file__)), "qt", "plugins"
     )
+
+# Qt will throw warning on Linux if fonts are not found
+if sys.platform.startswith("linux") and ci_and_not_headless:
+    os.environ["QT_QPA_FONTDIR"] = os.path.join(
+        os.path.dirname(os.path.abspath(__file__)), "qt", "fonts"
+    )