As shown in the Local Development Server Options documentation:
Python 2 is no longer supported by the community. We recommend that you migrate Python 2 apps to Python 3.
About Python 2 support in Google Cloud:
The Python community announced that it will sunset Python 2 on January 1, 2020, and are encouraging all developers to upgrade to Python 3 as soon as they can. In recognition that customers may need more time to migrate from Python 2 to Python 3, Google Cloud customers will be able to run Python 2 apps and use existing Python 2 client libraries after January 1, 2020.
Managed compute services, such as App Engine, will continue to provide a Python 2 runtime beyond January 1, 2020. Python 2 client libraries will continue to be available for download, but future major releases will only target Python 3.
—Google Cloud CLI
Google Cloud CLI version 274.0.0 introduces support for Python 3. Older versions of the gcloud CLI will remain available for download, but we recommend using version 274.0.0 or newer and migrating to Python 3 as soon as possible.
The best way to report this kind of issues is with issue tracker as you have done:
About Issue reports:
Google reviews every new issue report submitted by users. Sometimes one of our staff will ask for clarification or followup. After we're able to replicate the issue, we'll tell you that it's been forwarded to the appropriate team.
Depending on the circumstances, we may be able to provide periodic updates while an issue is being looked at, but usually we cannot provide too many specifics about the exact cause of an issue, or when it will be fixed.
When we've fixed an issue in production, we'll indicate this and then we'll close the issue.
If you need further assistance, you can create a Support case.