Arvados

Pausing this while we fix #17830

While testing this I found a couple of instances where we do

  try:
    ...
  except RealException as e:
    raise BetterExplanation('encountered error %s', str(e))

In Python 3, this causes a confusing report like this, which is not what we intended:

Traceback:
  (stack trace)
RealException: ...

During handling of the above exception, another exception occurred:

Traceback:
  (stack trace)
BetterExplanation: encountered error ...

Updated to "raise ... from None" to suppress the extra stack trace and the misleading "another exception occurred" text.

Since #13147 arv-put also appends the request ID to anything logged at "debug" or "error" level, so now it appears twice. Not sure whether we want to update arv-put to remove one of them.

2021-09-28 14:24:06 arvados.arv_put[2719] INFO: Resuming upload from cache file /home/tom/.cache/arvados/arv-put/5100a66866e71d151688c003f7e05230
0M / 0M 0.0% 2021-09-28 14:24:34 arvados.arv_put[2719] ERROR: arv-put: Error writing some blocks: block
 f555a8e1db0ef866c91b92db87275b7e+21155 raised KeepWriteError ([req-i6kwtgjylon7bsq0x4uk] failed to write
 f555a8e1db0ef866c91b92db87275b7e after 4 attempts (wanted (2, ['default']) copies but wrote (0, [])):
 service http://localhost:45621/ responded with 0 (7, 'Failed to connect to localhost port 45621:
 Connection refused'); service http://localhost:49069/ responded with 0 (7, 'Failed to connect to
 localhost port 49069: Connection refused')) (X-Request-Id: req-i6kwtgjylon7bsq0x4uk)

17779-request-id-in-exception @ ea5a800b643143baade1eb6c7f1760d366d92674 -- developer-run-tests: #2712

Applied in changeset arvados-private:commit:arvados|1441208182ced30e28f05611fbfa51674570dd1e.