54 lines
2.4 KiB
Markdown
54 lines
2.4 KiB
Markdown
For the record, there is a slight weirdness with how git-annex
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handles a signal like ctrl-c.
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For example:
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joey@gnu:~/tmp/b>git annex copy a b --to origin
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copy a (checking origin...) (to origin...)
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SHA256-s104857600--20492a4d0d84f8beb1767f6616229f85d44c2827b64bdbfb260ee12fa1109e0e
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3272 0% 0.00kB/s 0:00:00 ^C
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zsh: interrupt git annex copy a --to origin
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joey@gnu:~/tmp/b>
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rsync error: unexplained error (code 130) at rsync.c(549) [sender=3.0.9]
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Here git-annex exits before rsync has fully exited. Not a large problem
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but sorta weird.
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The culprit is `CmdLine.startup` in Utility.SafeCommand, which installs
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a default signal handler for SIGINT, which causes it to immediatly
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terminate git-annex. rsync, in turn, has its own SIGINT handler, which
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prints the message, typically later.
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(Why it prints that message and not its more usual message about having
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received a signal, I'm not sure?)
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It's more usual for a `system` like thing to block SIGINT, letting the child
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catch it and exit, and then detecting the child's exit status and terminating.
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However, since rsync *is* trapping SIGINT, and exiting nonzero explicitly,
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git-annex can't tell that rsync failed due to a SIGINT by examining the
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`waitpid` result.
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And, git-annex typically doesn't stop when a single child fails. In the
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example above, it would go on to copy `b` after a ctrl-c!
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A further complication is that git-annex is itself a child process
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of git, which does not block SIGINT either. So if git-annex blocks SIGINT,
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it will be left running in the background after git exits, and continuing
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with further actions too. (Perhaps its SIGINT handling is a bug in git.)
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Now, rsync does have a documented exit code it uses after a SIGINT.
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But other programs git-annex runs generally do not. So it would be possible
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to special case in support for rsync, blocking SIGINT while running it,
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noticing it exited with 20, and git-annex then stopping. But this is
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ugly and failure prone if rsync's code 20 changes. And it only
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would fix the rsync case, not helping with other commands like wget, unless
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it assumes they never trap SIGINT on their own.
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Which is why the current behavior of not blocking SIGINT was chosen,
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as a less bad alternative. Still, I'd like to find a better one.
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--[[Joey]]
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[[!tag confirmed]]
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> [[done]], I think this was fixed long ago, git-annex no longer installs a
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> sigint handler and I interrupt it all the time and it behaves as I would
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> expect and not as shown here --[[Joey]]
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