That was added back in 2013 commit 2af652e1b8
and I'm a bit unclear about the reasons.
It seemed that, at the time, receive.denyNonFastforwards=true, which is
the default in a repo created by git init --shared --bare (but not
without --shared), which the assistant did, caused problems syncing.
But even at the time the bug report showed an error message clearly
explaining that it was a non-fast-forward push being denied.
I tried it with the current version, and since git-annex sync pulls
from the bare repo and merges, it pushes a fast-forward. So there's no
failure to push. (There could be one if another push happened after the
pull, but you'd want it to fail then presumably.)
I'm not 100% sure what changed to make it not be a problem, but I know
I've seen this message in many circumstances and I can't ever recall it
having anything to do with any issue that prevented a push.
Based on doc/forum/non_fast_forward_error_with_git_annex_sync.mdwn,
which showed the problem when syncing from a direct mode repo,
and on doc/forum/receiving_indirect_renames_on_direct_repo___63__/comment_3_0246fff6c7c75f6be45bd257ec3872a5._comment
which seems to show the problem was actually a problem pulling,
I think there's a good chance that the problem actually involved direct
mode.
* Added sync --only-annex, which syncs the git-annex branch and annexed
content but leaves managing the other git branches up to you.
* Added annex.synconlyannex git config setting, which can also be set with
git-annex config to configure sync in all clones of the repo.
Use case is then the user has their own git workflow, and wants to use
git-annex without disrupting that, so they sync --only-annex to get the
git-annex stuff in sync in addition to their usual git workflow.
When annex.synconlyannex is set, --not-only-annex can be used to override
it.
It's not entirely clear what --only-annex --commit or --only-annex
--push should do, and I left that combination not documented because I
don't know if I might want to change the current behavior, which is that
such options do not override the --only-annex. My gut feeling is that
there is no good reasons to use such combinations; if you want to use
your own git workflow, you'll be doing your own committing and pulling
and pushing.
A subtle question is, how should import/export special remotes be handled?
Importing updates their remote tracking branch and merges it into master.
If --only-annex prevented that git branch stuff, then it would prevent
exporting to the special remote, in the case where it has changes that
were not imported yet, because there would be a unresolved conflict.
I decided that it's best to treat the fact that there's a remote tracking
branch for import/export as an implementation detail in this case. The more
important thing is that an import/export special remote is entirely annexed
content, and so it makes a lot of sense that --only-annex will still sync
with it.
Fix support for repositories tuned with annex.tune.branchhash1=true,
including --all not working and git-annex log not displaying anything for
annexed files.
fsck --from remote: Fix a concurrency bug that could make it incorrectly
detect that content in the remote is corrupt, and remove it, resulting in
data loss.
* When git-annex is built with a ssh that does not support ssh connection
caching, default annex.sshcaching to false, but let the user override it.
* Improve warning messages further when ssh connection caching cannot
be used, to clearly state why.
