Running incoming and outgoing commands in parallel isn’t always supported

[palant]

This code will run hg incoming and hg outgoing in parallel which is problematic:

vscode-hg/src/repository.ts

Lines 1134 to 1143 in 923f511

	await Promise.all([
	this.countIncomingAfterDelay(
	expectedDeltas && expectedDeltas.incoming,
	delayMillis
	),
	this.countOutgoingAfterDelay(
	expectedDeltas && expectedDeltas.outgoing,
	delayMillis
	),
	]);

I have hg-git extension installed which locks the repository for these commands. Consequently, running them in parallel results in an error:

Traceback (most recent call last):
  File "/usr/lib64/python3.10/site-packages/dulwich/file.py", line 150, in __init__
    fd = os.open(
FileExistsError: [Errno 17] File exists: b'repo/.hg/git/refs/heads/main.lock'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/hg", line 61, in <module>
    dispatch.run()
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 144, in run
    status = dispatch(req)
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 250, in dispatch
    status = _rundispatch(req)
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 294, in _rundispatch
    ret = _runcatch(req) or 0
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 470, in _runcatch
    return _callcatch(ui, _runcatchfunc)
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 480, in _callcatch
    return scmutil.callcatch(ui, func)
  File "/usr/lib64/python3.10/site-packages/mercurial/scmutil.py", line 153, in callcatch
    return func()
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 460, in _runcatchfunc
    return _dispatch(req)
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 1273, in _dispatch
    return runcommand(
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 918, in runcommand
    ret = _runcommand(ui, options, cmd, d)
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 1285, in _runcommand
    return cmdfunc()
  File "/usr/lib64/python3.10/site-packages/mercurial/dispatch.py", line 1271, in <lambda>
    d = lambda: util.checksignature(func)(ui, *args, **strcmdopt)
  File "/usr/lib64/python3.10/site-packages/mercurial/util.py", line 1887, in check
    return func(*args, **kwargs)
  File "/usr/lib64/python3.10/site-packages/mercurial/commands.py", line 5022, in outgoing
    return hg.outgoing(ui, repo, dests, opts)
  File "/usr/lib64/python3.10/site-packages/mercurial/hg.py", line 1433, in outgoing
    o, others = _outgoing(ui, repo, dests, opts, subpath=subpath)
  File "/usr/lib64/python3.10/site-packages/mercurial/hg.py", line 1379, in _outgoing
    outgoing = discovery.findcommonoutgoing(
  File "hg-git/hggit/gitrepo.py", line 152, in findcommonoutgoing
    heads = repo.githandler.get_refs(other.path)[0]
  File "hg-git/hggit/git_handler.py", line 437, in get_refs
    exportable = self.export_commits()
  File "hg-git/hggit/git_handler.py", line 432, in export_commits
    return self.update_references()
  File "hg-git/hggit/git_handler.py", line 1639, in update_references
    self.git.refs[git_ref] = git_sha
  File "/usr/lib64/python3.10/site-packages/dulwich/refs.py", line 377, in __setitem__
    self.set_if_equals(name, None, ref)
  File "/usr/lib64/python3.10/site-packages/dulwich/refs.py", line 931, in set_if_equals
    with GitFile(filename, "wb") as f:
  File "/usr/lib64/python3.10/site-packages/dulwich/file.py", line 92, in GitFile
    return _GitFile(filename, mode, bufsize, mask)
  File "/usr/lib64/python3.10/site-packages/dulwich/file.py", line 156, in __init__
    raise FileLocked(filename, self._lockfilename)
dulwich.file.FileLocked: (b'repo/.hg/git/refs/heads/main', b'repo/.hg/git/refs/heads/main.lock')

Maybe drop Promise.all() here and run the commands sequentially?