[[!comment format=mdwn
 username="yarikoptic"
 avatar="http://cdn.libravatar.org/avatar/f11e9c84cb18d26a1748c33b48c924b4"
 subject="comment 3"
 date="2022-05-24T21:05:03Z"
 content="""
I should have looked above in that stderr where interesting part begins with possibly relevant extra complaints:

```
    52  2022-05-20T19:27:59-0400 [INFO    ] backups2datalad Downloading files for Dandiset 000026
    53  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS10_stain-NeuN_chunk-04_SPIM.ome.tif (from web...) 
    54    failed to commit changes to sqlite database: Just SQLite3 returned ErrorBusy while attempting to perform step: database is locked
    55    CallStack (from HasCallStack):
    56      error, called at ./Database/Handle.hs:91:26 in main:Database.Handle
    57  (Delaying 1s before retrying....)
    58  ok
    59  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS10_stain-NeuN_chunk-02_SPIM.ome.tif (from web...) 
    60    thread blocked indefinitely in an MVar operation
    61  (Delaying 1s before retrying....)
    62  ok
    63  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS12_stain-Calretinin_chunk-00_SPIM.ome.tif (from web...) 
    64    thread blocked indefinitely in an MVar operation
    65  (Delaying 1s before retrying....)
    66  ok
    67  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS12_stain-NeuN_chunk-01_SPIM.ome.tif (from web...) 
    68    thread blocked indefinitely in an MVar operation
    69  (Delaying 1s before retrying....)
    70  ok
    71  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS12_stain-Nuclei_chunk-01_SPIM.ome.tif (from web...) 
    72    thread blocked indefinitely in an MVar operation
    73  (Delaying 1s before retrying....)
    74  ok
    75  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS12_stain-Nuclei_chunk-05_SPIM.ome.tif (from web...) 
    76    failed to commit changes to sqlite database: Just SQLite3 returned ErrorBusy while attempting to perform step: database is locked
    77    CallStack (from HasCallStack):
    78      error, called at ./Database/Handle.hs:91:26 in main:Database.Handle
    79  (Delaying 1s before retrying....)
    80  ok
    81  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS12_stain-Nuclei_chunk-06_SPIM.ome.tif (from web...) 
    82    thread blocked indefinitely in an MVar operation
    83  (Delaying 1s before retrying....)
    84  ok
    85  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS13_stain-NeuN_chunk-02_SPIM.ome.tif (from web...) 
    86    thread blocked indefinitely in an MVar operation
    87  (Delaying 1s before retrying....)
    88  ok
    89  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS14_stain-Calretinin_chunk-01_SPIM.ome.tif (from web...) 
    90    thread blocked indefinitely in an MVar operation
    91  (Delaying 1s before retrying....)
    92  ok
    93  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS13_stain-Nuclei_chunk-05_SPIM.ome.tif (from web...) 
    94    thread blocked indefinitely in an MVar operation
    95  (Delaying 1s before retrying....)
    96  ok
    97  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS14_stain-NeuN_chunk-07_SPIM.ome.tif (from web...) 
    98    thread blocked indefinitely in an MVar operation
    99  (Delaying 1s before retrying....)
   100  ok
   101  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS13_stain-Nuclei_chunk-08_SPIM.ome.tif (from web...) 
   102    thread blocked indefinitely in an MVar operation
   103  (Delaying 1s before retrying....)
   104  ok
   105  get rawdata/sub-I46/ses-SPIM/micr/sub-I46_ses-SPIM_sample-BrocaAreaS14_stain-NeuN_chunk-10_SPIM.ome.tif (from web...) 
   106    thread blocked indefinitely in an MVar operation
   107  (Delaying 1s before retrying....)
```

`strace -f -p 1683786` ends with

```
[pid 1683799] <... sched_yield resumed>) = 0
[pid 1683798] sched_yield( <unfinished ...>
[pid 1683810] futex(0x7fd5cc000c08, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid 1683803] futex(0x7fd5c0000be8, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid 1683799] futex(0x5b180ec, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid 1683798] <... sched_yield resumed>) = 0
[pid 1683798] futex(0x7fd5d8000bec, FUTEX_WAIT_PRIVATE, 0, NULL <unfinished ...>
[pid 1683787] <... read resumed>\"\1\0\0\0\0\0\0\0\", 8) = 8
[pid 1683787] futex(0x4a4844c, FUTEX_WAIT_PRIVATE, 0, NULL
```

I will now interrupt that process to \"proceed\", knowing what to do next time would be helpful

"""]]
