tests/test-abort-checkin.t

cache: avoid warming the fnodetags cache after clone

That cache can quite expensive to compute on large repository as not that `hg
clone` is warming all cache, this can introduces a significant slowdown for
clone time[1]. As a stop gap measure introduce a quick fix for
that on stable, skipping the fnodetags cache post-clone.

[1] https://www.mercurial-scm.org/pipermail/mercurial/2021-April/052679.html

Differential Revision: https://phab.mercurial-scm.org/D10695

  $ cat > abortcommit.py <<EOF
  > from mercurial import error
  > def hook(**args):
  >     raise error.Abort(b"no commits allowed")
  > def reposetup(ui, repo):
  >     repo.ui.setconfig(b"hooks", b"pretxncommit.nocommits", hook)
  > EOF
  $ abspath=`pwd`/abortcommit.py

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > mq =
  > abortcommit = $abspath
  > EOF

  $ hg init foo
  $ cd foo
  $ echo foo > foo
  $ hg add foo

mq may keep a reference to the repository so __del__ will not be
called and .hg/journal.dirstate will not be deleted:

  $ hg ci -m foo
  error: pretxncommit.nocommits hook failed: no commits allowed
  transaction abort!
  rollback completed
  abort: no commits allowed
  [255]
  $ hg ci -m foo
  error: pretxncommit.nocommits hook failed: no commits allowed
  transaction abort!
  rollback completed
  abort: no commits allowed
  [255]

  $ cd ..