Intermittent v9.18 build fails on Fedora COPR buildsys, always in `netmgr_test` ?

[PGNet Dev]

I'm building bind9 (v9.18.5, atm) on Fedora's COPR infrastructure.

Building for Fedora 36, 37 & Rawhide, the builds FAIL randomly/intermittently here

For example, with no changes to any source/spec, simply triggering rebuilds, over a period of just a few hours,


  Time                   F36   F37   Rawhide  build URL
  --------------------   ----  ----  -------  ----------
  2022-08-29 15:58 EDT   OK    FAIL  OK       https://copr.fedorainfracloud.org/coprs/pgfed/bind/build/4784469/

  2022-08-29 14:23 EDT   FAIL  OK    OK       https://copr.fedorainfracloud.org/coprs/pgfed/bind/build/4784210/

  2022-08-29 11:49 EDT   OK    OK    OK       https://copr.fedorainfracloud.org/coprs/pgfed/bind/build/4776394/

I'm trying to get a handle on cause ...

Local builds on my own infrastructure are always successful; the issue's only on COPR.

The FAILs are always in `netmgr_test` unittests ...

looking at netmgr test source, my as-yet-unfounded suspicion is that these timeouts

   https://github.com/isc-projects/bind9/blob/v9_18_5/tests/isc/netmgr_test.c#L116

are intermittently hitting limits -- only in COPR/online.  perhaps for specific transport?

I also note that -- in main, upstream, 3 days ago -- netmgr tests are being split up, into separate per-transport tests,

   https://github.com/isc-projects/bind9/commit/37a1be5acc32244cec03cedc1bd46bc4aa0fbc18

I'm not clear what specific problem is being solved by that split, but imagine that it might well have an effect on builds @ COPR.

I've not been able to get detailed test FAIL logs from COPR builds (local builds do not FAIL).  currently, @ #fedora-buildsys, did manage to get a reproducer of the build FAIL; I'm hoping I might get access to those FAIL logs via a manual COPR build.


Anyone here seen similar issues with netmgr, or maybe have a clue?

Fwiw, I've initially filed at RH BZ already:

   https://bugzilla.redhat.com/show_bug.cgi?id=2122010

; no response there yet.