Please describe the problem.
I think I never saw that before. The only thing which differs now I think is the version of git-annex on this box:
$> git annex get --from origin --debug 'sub-qa/ses-20180312/func/sub-qa_ses-20180312_task-rest_acq-p2Xs4X35mm_bold.nii.gz'
[2018-09-21 23:26:38.299280879] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","show-ref","git-annex"]
[2018-09-21 23:26:38.303220623] process done ExitSuccess
[2018-09-21 23:26:38.311081622] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","show-ref","--hash","refs/heads/git-annex"]
[2018-09-21 23:26:38.314302424] process done ExitSuccess
[2018-09-21 23:26:38.314584504] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","log","refs/heads/git-annex..4f0e8cd9a43b003228c3898133b1e200f9bdfc22","--pretty=%H","-n1"]
[2018-09-21 23:26:38.321260451] process done ExitSuccess
[2018-09-21 23:26:38.321567411] chat: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","cat-file","--batch"]
[2018-09-21 23:26:38.322235784] chat: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","cat-file","--batch-check=%(objectname) %(objecttype) %(objectsize)"]
[2018-09-21 23:26:38.327995657] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","ls-files","--cached","-z","--","sub-qa/ses-20180312/func/sub-qa_ses-20180312_task-rest_acq-p2Xs4X35mm_bold.nii.gz"]
get sub-qa/ses-20180312/func/sub-qa_ses-20180312_task-rest_acq-p2Xs4X35mm_bold.nii.gz (from origin...)
[2018-09-21 23:26:38.336441538] chat: ssh ["bids@rolando.cns","-S",".git/annex/ssh/bids@rolando.cns","-o","ControlMaster=auto","-o","ControlPersist=yes","-T","git-annex-shell 'p2pstdio' '/inbox/BIDS/dbic/QA' '--debug' 'ba8f2cea-f229-422c-82be-6580e5e07ed5' --uuid 6384a551-a41d-4290-b186-9258befede97"]
[2018-09-21 23:26:39.94999901] P2P > ERROR auth failed
fd:19: hClose: resource vanished (Broken pipe)
failed
[2018-09-21 23:26:39.951838683] read: ssh ["-O","stop","-S","bids@rolando.cns","-o","ControlMaster=auto","-o","ControlPersist=yes","localhost"]
[2018-09-21 23:26:39.960970417] process done ExitSuccess
[2018-09-21 23:26:39.961786471] process done ExitSuccess
[2018-09-21 23:26:39.962311637] process done ExitSuccess
$> git annex version
git-annex version: 6.20180913+git33-g2cd5a723f-1~ndall+1
build flags: Assistant Webapp Pairing S3(multipartupload)(storageclasses) WebDAV Inotify DBus DesktopNotify ConcurrentOutput TorrentParser MagicMime Feeds Testsuite
dependency versions: aws-0.19 bloomfilter-2.0.1.0 cryptonite-0.25 DAV-1.3.2 feed-1.0.0.0 ghc-8.2.2 http-client-0.5.12 persistent-sqlite-2.8.1.2 torrent-10000.1.1 uuid-1.3.13 yesod-1.6.0
key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_224 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 BLAKE2B256E BLAKE2B256 BLAKE2B512E BLAKE2B512 BLAKE2B160E BLAKE2B160 BLAKE2B224E BLAKE2B224 BLAKE2B384E BLAKE2B384 BLAKE2S256E BLAKE2S256 BLAKE2S160E BLAKE2S160 BLAKE2S224E BLAKE2S224 BLAKE2SP256E BLAKE2SP256 BLAKE2SP224E BLAKE2SP224 SHA1E SHA1 MD5E MD5 WORM URL
remote types: git gcrypt p2p S3 bup directory rsync web bittorrent webdav adb tahoe glacier ddar hook external
operating system: linux x86_64
supported repository versions: 3 5 6
upgrade supported from repository versions: 0 1 2 3 4 5
local repository version: 5
$> ssh -S .git/annex/ssh/bids@rolando.cns bids@rolando.cns ls /inbox/BIDS/dbic/QA
Dartmouth College, Department of Psychological and Brain Sciences
Authorized access only
CHANGES
code
...
$> ssh -S .git/annex/ssh/bids@rolando.cns bids@rolando.cns git annex version
Dartmouth College, Department of Psychological and Brain Sciences
Authorized access only
git-annex version: 6.20180115-g56b56033a
so ssh connection seems to be ok
what could it be?
The other difference is that the non-working machine is using IPv6 and IPv4, while the working machine is just IPv4
Downgrading (testing on local laptop) local git-annex all the way down (didn't try intermediates yet) to 6.20170101-1+deb9u2 helped - I can fetch data from that server.
My wild guess is that it all relates to the fact that remote git-annex-shell, being outdated, has no clue about
p2pstdiocommand, and local new git-annex doesn't fall back anyhow to use some other way to transfer.FWIW, here is what I see if I just try to invoke directly
so - exit code is
1(happen annex decides on exit code about availability of p2pstdio)The only new change in 6.20180913 that might somehow affect this is b18fb1e343e9654207fbebacf686659c75d0fb4c. But I don't see how it could really.
Since ssh seems to be displaying a motd when running a noninteractive command, I think that git-annex must be seeing that motd where it expects to see the P2P protocol.
Although it may be that ssh -T avoids the motd display. (But unfortunately your transcript using -T trims out exactly that part!) I didn't think ssh normally displays motd when not running a login shell. Perhaps it's something to do with your shell and not ssh.
git-annex will fall back to not using p2pstdio, but only if the command exits nonzero without ssh sending anything to stdout.
indeed I do have /etc/issue (not motd) displayed even when with -T:
replicated on another host with a VERY outdated annex (5.20141125), but where there is no issue or motd:
so I think it is incorrectly handles this failure and doesn't fall back to ssh/rsync. nothing to do with motd/issue
I tried configuring sshd with PrintMotd yes, that actually resulted in double motd on interactive login, but still none on noninteractive login, and doesn't cause this problem.
I tried making ~/.bashrc echo some stuff. That also didn't reproduce the problem, though debug does have this:
It does not give up, but goes on to use rsync. Although rsync unsurprisingly also fails "protocol version mismatch -- is your shell clean?".
Still, this seems to indicate that the motd display shown in your transcripts is at the root of the problem, although I've not fully replicated the circumstances and will need more information to get further on this.
Ok, reproduced by downgrading git-annex, so it is a reversion in the fallback from p2pstdio.
It is indeed caused by b18fb1e343e9654207fbebacf686659c75d0fb4c, because that adds a new ProtocolEOF value, and postAuth has a fallthrough case that tries to then send a ERROR message back over the connection, but by that time the pipe has closed.
So that was an easy fix. I do still wonder how a system that displays /etc/issue or whatever to noninteractive logins could have ever worked with rsync or git-annex. But if that system doesn't work after this fix, it's an unrelated problem.
FWIW confirming that the issue is resolved for my attempts while interacting with that very old git-annex on a server side