Package: unison
Version: 2.48.3-1
Severity: important
Dear Maintainer,
* What led up to the situation?
I tried to sync using unison between an up-to-date Debian stretch and a Ubuntu
xenial host, both have the same unison version:
Debian:
ii unison 2.48.3-1 amd64 file-synchronization tool for Unix
and Windows
Ubuntu:
ii unison 2.48.3-1ubuntu1 amd64
file-synchronization tool for Unix and Windows
I discovered that the Debian side crashes whenever a file with size 701 bytes or
bigger has to be transferred from debian to ubuntu.
The error does NOT appear if the file on the other side doesn't exist yet.
The error also doesn't appear if both systems are Ubuntu or if both are Debian.
== Here is a test matrix: ==
debian file
=700 bytes =701 bytes
ubuntu file =700 bytes d->u ok, u->d ok d->u ok, u->d ok
=701 bytes d->u ok, u->d ok d->u err, u->d ok
explanation: d->u means transfer from debian to ubuntu, no matter which side
runs unison, only the final direction of the file transfer is relevant, see logs
below.
== Error log when running on Debian side: ==
synctest@debian:~$ unison myfolder/ ssh://$remoteip/myfolder/
Contacting server...
Connected [//debian//home/synctest/myfolder -> //ubuntu//home/synctest/myfolder]
Looking for changes
Waiting for changes from server
Reconciling changes
local ubuntu
changed ====> changed testfile [] >
Proceed with propagating updates? [] y
Propagating updates
UNISON 2.48.3 started propagating changes at 13:31:35.72 on 01 May 2016
[BGN] Updating file testfile from /home/synctest/myfolder to
//ubuntu//home/synctest/myfolder
Uncaught exception Failure("input_value: bad bigarray kind")
Raised by primitive operation at file "/tmp/buildd/unison-2.48.3/remote.ml",
line 453, characters 18-45
Called from file "/tmp/buildd/unison-2.48.3/remote.ml", line 459, characters
23-61
Called from file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 75, characters
20-23
Re-raised at file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 135, characters
12-13
Called from file "list.ml", line 73, characters 12-15
Called from file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 31, characters
2-37
Called from file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 83, characters
17-46
Called from file "/tmp/buildd/unison-2.48.3/lwt/generic/lwt_unix_impl.ml", line
147, characters 6-40
Called from file "/tmp/buildd/unison-2.48.3/uitext.ml", line 490, characters
2-113
Called from file "/tmp/buildd/unison-2.48.3/uitext.ml", line 556, characters
38-66
Called from file "/tmp/buildd/unison-2.48.3/uitext.ml", line 718, characters
6-47
Called from file "/tmp/buildd/unison-2.48.3/uitext.ml", line 788, characters
6-90
Called from file "/tmp/buildd/unison-2.48.3/uitext.ml", line 810, characters
19-66
Called from file "/tmp/buildd/unison-2.48.3/uitext.ml", line 870, characters
21-43
== Error log when running on Ubuntu side: ==
synctest@ubuntu:~$ unison myfolder/ ssh://$remoteip/myfolder/
Contacting server...
Connected [//debian//home/synctest/myfolder -> //ubuntu//home/synctest/myfolder]
Looking for changes
Waiting for changes from server
Reconciling changes
local debian
changed <==== changed testfile [] <
Proceed with propagating updates? [] y
Propagating updates
UNISON 2.48.3 started propagating changes at 13:32:41.51 on 01 May 2016
[BGN] Updating file testfile from //debian//home/synctest/myfolder to
/home/synctest/myfolder
Unison failed: Uncaught exception Failure("input_value: bad bigarray kind")
Raised by primitive operation at file "/tmp/buildd/unison-2.48.3/remote.ml",
line 453, characters 18-45
Called from file "/tmp/buildd/unison-2.48.3/remote.ml", line 459, characters
23-61
Called from file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 75, characters
20-23
Re-raised at file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 135, characters
12-13
Called from file "list.ml", line 73, characters 12-15
Called from file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 31, characters
2-37
Called from file "/tmp/buildd/unison-2.48.3/lwt/lwt.ml", line 83, characters
17-46
Called from file "/tmp/buildd/unison-2.48.3/lwt/generic/lwt_unix_impl.ml", line
147, characters 6-40
Called from file "/tmp/buildd/unison-2.48.3/main.ml", line 202, characters 6-24
Called from file "/tmp/buildd/unison-2.48.3/main.ml", line 131, characters 4-9
Fatal error: Lost connection with the server
^^^ you can see, Ubuntu only crashes because the remote side aborts the
connection
== How to reproduce ==
I used docker to reproduce this bug. Using the following commands in two
separate terminals:
# one of the following for each terminal
docker run -h debian -ti debian:stretch
docker run -h ubuntu -ti ubuntu:xenial
# inside docker as root, in both terminals (environment preparation)
apt-get update
apt-get install -y unison
apt-get install -y openssh-server iproute
/etc/init.d/ssh restart
adduser synctest
su - synctest
# now as user synctest, still inside docker (again environment preparation)
ip a
# or: ip a | grep 'scope global eth0' | awk '{print $2}' | cut -d/ -f1
remoteip= #<- enter remote IP here
mkdir myfolder
touch myfolder/file-$$
ssh-keygen
ssh-copy-id $remoteip
ssh $remoteip "hostname ; echo ok"
unison -version
# both report as: unison version 2.48.3
# now, in one terminal, call unison once to initialize the db:
unison myfolder/ ssh://$remoteip/myfolder/
# for testing, you can now call the following commands (dd on both sides,
unison on one side):
dd if=/dev/urandom of=myfolder/testfile bs=701 count=1
unison myfolder/ ssh://$remoteip/myfolder/
-- System Information:
Debian Release: stretch/sid
APT prefers testing-updates
APT policy: (500, 'testing-updates'), (500, 'testing')
Architecture: amd64 (x86_64)
Kernel: Linux 4.4.0-21-generic (SMP w/8 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Init: unable to detect
Versions of packages unison depends on:
ii libc6 2.22-5
Versions of packages unison recommends:
ii openssh-client [ssh-client] 1:7.2p2-4
Versions of packages unison suggests:
pn unison-all <none>
-- no debconf information
