              fonts.setdefault(font.name, dict())["bold"] = True
      valid_fonts = {key for key, val in fonts.items() if len(val) == 2}
      retval = sorted(list(valid_fonts.intersection(tk_font.families())))
      return ["default"] + retval
 
</s> remove                              for ftype in filetypes[key] if ftype[0] != "All files"]))
 </s> add                                        for ftype in filetypes[key] if ftype[0] != "All files"])) </s> remove     @classmethod
    def _set_default_font(cls):
        """ Set the default font.

        For macOS and Windows, this just pulls back the system default font.

        For Linux, quite often the default is not ideal, so we try to pull a sane default from
        installed fonts.
        """
        if platform.system() == "Linux":
            for family in ("DejaVu Sans", "Noto Sans", "Nimbus Sans"):
                if family in tk.font.families():
                    logger.debug("Setting default font to: '%s'", family)
                    tk.font.nametofont("TkDefaultFont").configure(family=family)
                    tk.font.nametofont("TkHeadingFont").configure(family=family)
                    tk.font.nametofont("TkMenuFont").configure(family=family)
                    break
        return tk.font.nametofont("TkDefaultFont").configure()["family"]

 </s> add  </s> remove         self._default_font = self._set_default_font()
 </s> add         self._default_font = tk.font.nametofont("TkDefaultFont").configure()["family"]
    if not retval:
        # Return the font list with any @prefixed or non-Unicode characters stripped and default
        # prefixed
        logger.debug("No bold/regular fonts found. Running simple filter")
        retval = sorted([fnt for fnt in tk_font.families()
                         if not fnt.startswith("@") and not any([ord(c) > 127 for c in fnt])])
              fonts.setdefault(font.name, dict())["bold"] = True
      valid_fonts = {key for key, val in fonts.items() if len(val) == 2}
      retval = sorted(list(valid_fonts.intersection(tk_font.families())))
    if not retval:
        # Return the font list with any @prefixed or non-Unicode characters stripped and default
        # prefixed
        logger.debug("No bold/regular fonts found. Running simple filter")
        retval = sorted([fnt for fnt in tk_font.families()
                         if not fnt.startswith("@") and not any([ord(c) > 127 for c in fnt])])
      return ["default"] + retval
keep keep add keep
 GUI - Revert Conda default font fix 
lib/gui/_config.py