bundle2: print "error:abort" message to stderr instead of stdout It seems like the server's message is something you'd like to see even with `--quiet`. It's clearly part of the error. Differential Revision: https://phab.mercurial-scm.org/D9954

narrow: add --no-backup option for narrowing Most of our users at Google use Mercurial on a file system that keeps backups of previous versions of all files, including those in `.hg/`. They therefore don't need a separate backup in the file system when narrowing their repo (which they typically do by running `hg tracked --auto-remove-includes`). Backups can be very slow. `hg strip` already has a `--no-backup` option. This patch adds the same option to `hg tracked --removeinclude/--addexclude`. Differential Revision: https://phab.mercurial-scm.org/D9951

debugdiscovery: add flags to run discovery on subsets of the local repo Generating new repository using strip of local clone is very expensive for large repositories. And such large repository are the most likely to requires debugging around discovery. So we add a simple way to run discovery using provided sets of heads. Differential Revision: https://phab.mercurial-scm.org/D9945