Repo format conversion strategy?

[Doug Lee]

I've experimented with converting from .bzr to .git format for some of my projects, but encountered these roadblocks:

* The fastexport | fastimport techniques fail with file reference errors.
* Modifying that to use marks (an AI suggestion) taught me that Git can't read a brz marks file (without massaging that I didn't do, perhaps).
* reposurgeon fails with a reference error to what looks like a branch or folder name.
* brz push --lossy to a git inited repo works but sends over zero of my tags.

Is there a reliable approach, and it's ok if I need to sh- or Python-script one, for converting potentially over 100 or so projects' format from .bzr to .git?

Details:
brz version 3.3.11
Git version 2.48.1
Test env: Ubuntu 25.04 (Plucky) as a WSL2 instance on Windows 11 25H2
Largest test brz repo has about 2700 revisions.
Most of my repos have only one branch but some have a few more.

-- 
Doug Lee                 dgl at dlee.org                http://www.dlee.org
The very smart may feel they have nothing to learn from anyone;
The very wise will find something to learn from everyone.  (7/14/01)