code: def fix_trustdb(cls, trustdb=None):
      
      if trustdb is None:
          trustdb = os.path.join(cls.homedir, 'trustdb.gpg')
      export_proc = cls._open_subprocess(['--export-ownertrust'])
      import_proc = cls._open_subprocess(['--import-ownertrust'])
      _util._threaded_copy_data(export_proc.stdout, import_proc.stdin)
      export_proc.wait()
      import_proc.wait()
docs: Attempt to repair a broken trustdb.gpg file.
  
      GnuPG>=2.0.x has this magical-seeming flag: `--fix-trustdb`. You'd think
      it would fix the the trustdb. Hah! It doesn't. Here's what it does
      instead::
  
        (gpg)~/code/python-gnupg $ gpg2 --fix-trustdb
        gpg: You may try to re-create the trustdb using the commands:
        gpg:   cd ~/.gnupg
        gpg:   gpg2 --export-ownertrust > otrust.tmp
        gpg:   rm trustdb.gpg
        gpg:   gpg2 --import-ownertrust < otrust.tmp
        gpg: If that does not work, please consult the manual
  
      Brilliant piece of software engineering right there.
  
      :param str trustdb: The path to the trustdb.gpg file. If not given,
                          defaults to :file:`trustdb.gpg` in the current GnuPG
                          homedir.