PR: Return original font directory when font user installation load fails

qtawesome/iconic_font.py

@@ -725,7 +725,28 @@ def _install_fonts(self, fonts_directory, system_wide=False):
                             # Possible permission error when trying to remove
                             # a font which potentially is already in use
                             # See spyder-ide/qtawesome#236
-                            continue
+                            pass
+                        # Regardless whether the font file is actually removed,
+                        # we need to return here where the font file is
+                        # originally located since the load failed. With that,
+                        # a `FontError` can be eventually raised with useful
+                        # information (i.e not being able to load bundled
+                        # fonts, saying that the fonts are located in the
+                        # QtAwesome `fonts` directory and manual configuration
+                        # is needed to allow them). Also, if we don't detected
+                        # that the font being available from the system fonts
+                        # directory, a warning with a more specific suggestion
+                        # (i.e. to install the font manually) is shown.
+                        # See spyder-ide/qtawesome#264
+                        if not os.path.isfile(os.path.join(system_fonts_dir, filename)):
+                            warnings.warn(
+                                "Font at '{0}' could not be loaded. If "
+                                "possible, install it system wide to make it "
+                                "available to QtAwesome. The source file to "
+                                "be manually installed can be found at "
+                                "'{1}'".format(dst_path, src_path)
+                            )
+                        return fonts_directory
 
                     # Store the fontname/filename in the registry
                     fontname = os.path.splitext(filename)[0]