Re: [BUG] t9801 and t9803 broken on next

From: Lars Schneider <larsxschneider@gmail.com>
Date: May 14, 2016, 08:04 UTC
Message-ID: <4830D469-3885-4010-9A04-D809F0C6159D@gmail.com>
In-Reply-To: <xmqqpospap8g.fsf@gitster.mtv.corp.google.com>

Show 29 quoted lines

> On 13 May 2016, at 18:37, Junio C Hamano <gitster@pobox.com> wrote:
> 
> Eric Wong <e@80x24.org> writes:
> 
>> Lars Schneider <larsxschneider@gmail.com> wrote:
>>> Hi,
>>> 
>>> t9801 and t9803 seem to be broken on next. A quick bisect indicates that d9545c7 
>>> "fast-import: implement unpack limit" might be the reason. (@gmane/292562).
>>> 
>>> Did anyone look into that already?
>> 
>> Just took a look (no p4, so couldn't run tests) and I guess it's
>> because the default changed and it doesn't generate tiny packs.
> 
> I looked at t9801 but I couldn't spot where it cares if the objects
> are in a (tiny) pack or stored as individual loose objects.  All the
> counting I saw was about rev-list/log output and they shouldn't care.
> 
> Are you saying that "git p4" itself breaks unless fast-import always
> writes a new (tiny) packfile?  That sounds quite broken, and setting
> unpacklimit to 0 does not sound like a sensible "fix".  Of course,
> if the test script is somehow looking at the number of packs or
> loose objects and declaring a failure, even when the resulting
> history in p4 and git are correct, then that is a different issue,
> and forcing to explode a tiny pack is a reasonable workaround.  I
> couldn't quite tell which the case is.
> 
> Puzzled.  Please help.

t9801 "import depot, branch detection" is the first test that fails with a fast import error: https://github.com/git/git/blob/78b384c29366e199741393e56030a8384110760d/t/t9801-git-p4-branch.sh#L110

fast-import crash report:
    fast-import process: 77079
    parent process     : 77077
    at 2016-05-14 07:48:40 +0000

fatal: offset beyond end of packfile (truncated pack?)

Most Recent Commands Before Crash
---------------------------------
  commit refs/remotes/p4/master
  mark :1
  committer Dr. author <author@example.com> 1463212118 +0000
  data <<EOT
  M 100644 inline f1
  data 3
  
  commit refs/remotes/p4/master
  mark :2
  committer Dr. author <author@example.com> 1463212118 +0000
  data <<EOT
  M 100644 inline f2
  data 3
  
  commit refs/remotes/p4/master
  mark :4
  committer Dr. author <author@example.com> 1463212118 +0000
  data <<EOT
  M 100644 inline f4
  data 3
  
  checkpoint
  commit git-p4-tmp/6
  mark :6
  committer Dr. author <author@example.com> 1463212118 +0000
  data <<EOT
  M 100644 inline f1
  data 3
  M 100644 inline f2
  data 3
  M 100644 inline f4
  data 3
  
  checkpoint
  progress checkpoint
  commit refs/remotes/p4/depot/branch2
  mark :6
  committer Dr. author <author@example.com> 1463212118 +0000
  data <<EOT
  from 1ab0d5b43b6070682f8bd6f3fd674d4fcddd9345
* M 100644 inline f1

Active Branch LRU
-----------------
    active_branches = 2 cur, 5 max

  pos  clock name
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1)      4 git-p4-tmp/6
   2)      3 refs/remotes/p4/master

Inactive Branches
-----------------
git-p4-tmp/6:
  status      : active loaded
  tip commit  : 3aef1b3e7d821051780a89262f2e2fae33ed8af3
  old tree    : 30a8495449245cdb9626ef48902ba672cf76576f
  cur tree    : 30a8495449245cdb9626ef48902ba672cf76576f
  commit clock: 4
  last pack   : 0

refs/remotes/p4/master:
  status      : active loaded
  tip commit  : 1ab0d5b43b6070682f8bd6f3fd674d4fcddd9345
  old tree    : 30a8495449245cdb9626ef48902ba672cf76576f
  cur tree    : 30a8495449245cdb9626ef48902ba672cf76576f
  commit clock: 3
  last pack   : 0

refs/remotes/p4/depot/branch2:
  status      : loaded
  tip commit  : 1ab0d5b43b6070682f8bd6f3fd674d4fcddd9345
  old tree    : 30a8495449245cdb9626ef48902ba672cf76576f
  cur tree    : 30a8495449245cdb9626ef48902ba672cf76576f
  commit clock: 0
  last pack   :

Marks ----- :1 47474c2e749d579c63b375231c018289aa00cd0f :2 9c6b957c0b4d4991b8bbd17858aa2a271d2c76c3 :4 1ab0d5b43b6070682f8bd6f3fd674d4fcddd9345 :6 3aef1b3e7d821051780a89262f2e2fae33ed8af3

------------------- END OF CRASH REPORT

Show 6 quoted lines

> 
>> The easiest change is probably to call:
>> 
>> 	git config fastimport.unpackLimit 0
>> 
>> during setup like t9300 now does.

Unfortunately that seems not to help.

The problem seems to be related to the git-p4 branch import. I don't have time this weekend to look further into it, but I will try next week.

Cheers, Lars