Tried to pull source code using “repo init -u https://git.tizen.org/cgit/scm/manifest -b tizen -m unified_standard.xml”

Received the following error:

Downloading Repo source from https://gerrit.googlesource.com/git-repo
remote: Counting objects: 1, done
remote: Finding sources: 100% (38/38)
remote: Total 38 (delta 10), reused 38 (delta 10)
Unpacking objects: 100% (38/38), done.
Traceback (most recent call last):
  File “/home/dave/Tizen_Project1/.repo/repo/main.py”, line 42, in <module>
    from git_config import RepoConfig
  File “/home/dave/Tizen_Project1/.repo/repo/git_config.py”, line 770
    self._Set(f’superproject.{key}’, value)
                                  ^
SyntaxError: invalid syntax

What does this error mean?  I’m using the .gbs.conf file at https://docs.tizen.org/platform/developing/setting-up/.