[Debian-astro-maintainers] Bug#985395: TAP queries fail

[Markus Demleitner]

Package: gavodachs2-server
Version: 2.3+dfsg-1
Severety: important

When running a synchronous TAP query, output stops after the first
few bytes and the connection hangs.

To reproduce:  Run

  curl -FLANG=ADQL -FQUERY="SELECT TOP 1 * FROM tap_schema.tables" http://localhost:8080/tap/sync

against a freshly installed copy of DaCHS.

The server stops delivering bytes because its delivery code throws an
exception:

          File "/usr/lib/python3/dist-packages/gavo/svcs/streaming.py", line 145, in cleanup
            if self.isAlive():
        builtins.AttributeError: 'DataStreamer' object has no attribute 'isAlive'

The problem is that the code streaming out uses the isAlive method of
python threads that was deprecated in python 3.7 and dropped in
python 3.8.  Unfortunately, the package tests were run in Debian
stable, so this bug was missed.

Since TAP is what most people will use this package for, and this
affects essentially all uses of TAP, this is a fairly ugly thing.