TypeError: utf_8_encode() argument 1 must be str, not bytes

[Juan Francisco Cantero Hurtado]

Steps to reproduce the bug:

$ mkdir test
$ cd test
$ brz init --bzr
Created a standalone tree (format: 2a)
$ brz pull https://github.com/ziglang/zig.git,branch=master
Fetching from Git to Bazaar repository. For better performance, fetch into a Git repository.
Total 85760 (delta 0), reused 2 (delta 0), pack-reused 85756
brz: ERROR: TypeError: utf_8_encode() argument 1 must be str, not bytes

Traceback (most recent call last):
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/commands.py", line 1017, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/commands.py", line 1203, in run_bzr
    ret = run(*run_argv)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/commands.py", line 757, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/commands.py", line 782, in run
    return class_run(*args, **kwargs)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/builtins.py", line 1263, in run
    result = tree_to.pull(
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/workingtree.py", line 826, in pull
    count = self.branch.pull(source, overwrite, stop_revision,
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/branch.py", line 1043, in pull
    return InterBranch.get(source, self).pull(
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/branch.py", line 1119, in pull
    return self._basic_pull(stop_revision, overwrite, run_hooks,
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/branch.py", line 1058, in _basic_pull
    result.new_git_head, remote_refs = self._update_revisions(
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/branch.py", line 1017, in _update_revisions
    head, refs = self.fetch_objects(stop_revision, fetch_tags=None, tag_selector=tag_selector)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/branch.py", line 1008, in fetch_objects
    pack_hint, head, refs = interrepo.fetch_objects(
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/interrepo.py", line 580, in fetch_objects
    (pack_hint, last_rev) = import_git_objects(
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/fetch.py", line 519, in import_git_objects
    import_git_commit(repo, mapping, head, lookup_object,
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/git/fetch.py", line 446, in import_git_commit
    repo.add_revision(rev.revision_id, rev)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/bzr/vf_repository.py", line 771, in add_revision
    self._add_revision(rev)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/bzr/vf_repository.py", line 774, in _add_revision
    lines = self._serializer.write_revision_to_lines(revision)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/bzr/chk_serializer.py", line 104, in write_revision_to_lines
    return self.write_revision_to_string(rev).splitlines(True)
  File "/home/juanfra/temporal/venv-breezy/lib/python3.8/site-packages/breezy/bzr/chk_serializer.py", line 92, in write_revision_to_string
    revprops[encode_utf8(key)[0]] = encode_utf8(value)[0]
TypeError: utf_8_encode() argument 1 must be str, not bytes

brz 3.2.0dev on python 3.8.2 (Linux-5.6.4.a-1-hardened-x86_64-with-glibc2.2.5)
arguments: ['/home/juanfra/temporal/venv-breezy/bin/brz', 'pull',
    'https://github.com/ziglang/zig.git,branch=master']
plugins: bash_completion[3.2.0dev], changelog_merge[3.2.0dev],
    commitfromnews[3.2.0dev], cvs[3.2.0dev], darcs[3.2.0dev], email[3.2.0dev],
    fastimport[3.2.0dev], flake8[unknown], fossil[3.2.0dev], hg[3.2.0dev],
    launchpad[3.2.0dev], mtn[3.2.0dev], netrc_credential_store[3.2.0dev],
    news_merge[3.2.0dev], po_merge[3.2.0dev], propose[3.2.0dev],
    quilt[unknown], repodebug[3.2.0dev], rewrite[unknown], stats[3.2.0dev],
    svn[3.2.0dev], upload[3.2.0dev], weave_fmt[3.2.0dev],
    zsh_completion[3.2.0dev]
encoding: 'utf-8', fsenc: 'utf-8', lang: 'en_US.UTF-8'

*** Bazaar has encountered an internal error. This probably indicates a
    bug in Bazaar. You can help us fix it by filing a bug report at
        https://bugs.launchpad.net/brz/+filebug
    including this traceback and a description of the problem.

[Jelmer Vernooij (jelmer)]

Reproduced in trunk.

[Jelmer Vernooij (jelmer)]

> /breezy/bzr/chk_serializer.py(92)write_revision_to_string()
-> revprops[encode_utf8(key)[0]] = encode_utf8(value)[0]
(Pdb) p key
'git-extra'
(Pdb) p value
b'HG:rename-source hg\n'