[[!comment format=mdwn
 username="yarikoptic"
 avatar="http://cdn.libravatar.org/avatar/f11e9c84cb18d26a1748c33b48c924b4"
 subject="comment 18"
 date="2022-06-06T14:50:16Z"
 content="""
> I have made a standalone tarball built that way available here: https://downloads.kitenet.net/git-annex/linux/debuglocks/
> It should display a backtrace on stderr when the MVar deadlock happens.

jinxing helped ... thought I thought to complain that I don't see any traceback but apparently it is due to `-J5` (I guess) and lines being ovrewritten, but I managed to `Ctrl-s` at a point showing

```
get 0/0/0/3/5/50 (from web...)
MVar deadlock detected CallStack (from HasCallStack):
  debugLocks, called at ./Database/Queue.hs:55:30 in main:Database.Queue
  thread blocked indefinitely in an MVar operation
(Delaying 1s before retrying....)
```

which when I let it go became smth like

```
get 0/0/0/3/0/98 (from web...)
  thread blocked indefinitely in an MVar operation
(Delaying 1s before retrying....)
ok
get 0/0/0/3/1/111 (from web...) ok
```

and reconfirmed for those in screenlog I quickly collected:

```
(base) dandi@drogon:~$ grep debugLocks screenlog.3
  debugLocks, called at ./Database/Queue.hs:55:30 in main:Database.Queue
  debugLocks, called at ./Database/Queue.hs:55:30 in main:Database.Queue
  debugLocks, called at ./Database/Queue.hs:55:30 in main:Database.Queue
  debugLocks, called at ./Database/Queue.hs:55:30 in main:Database.Queue
  debugLocks, called at ./Database/Queue.hs:55:30 in main:Database.Queue
```

"""]]
