seahorse buildfarm issues

hi all!

seahorse is struggling to submit buildfarm reports for a few days now.
there seems to a rather weird thing going on since what appears to
happen is that the build fails during "make check" with a crashing
postmaster but that crash is also hanging the buildfarm-script and so it
fails to submit a report.
After that event - there are no remaining processes in the taskmanager
but the OS still believes that some files (postgres.exe and some of the
files used in the regression test) are still in use.
The only way to recover from that (at least that I found as a
non-windows person) is a reboot of the whole VM - this results then in a
real large number of "application failed to initialize properly" errors
during shutdown(!). the applications mentioned in the errors are
more.exe,cmd.exe and diff.exe.
running the buildfarm script manually works just fine - which makes that
whole issue even more weird.

the following is in the postmaster.log:

ERROR: invalid input syntax for type circle: "(3,(1,2),3)"
ERROR: date/time value "current" is no longer supported
ERROR: date/time field value out of range: "1997-02-29"
ERROR: invalid input syntax for type time with time zone: "15:36:39
America/New_York"
LOG: server process (PID 2016) exited with exit code -1073741502
LOG: terminating any other active server processes
WARNING: terminating connection because of crash of another server process
DETAIL: The postmaster has commanded this server process to roll back
the current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.
HINT: In a moment you should be able to reconnect to the database and
repeat your command.
WARNING: terminating connection because of crash of another server process
DETAIL: The postmaster has commanded this server process to roll back
the current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.
HINT: In a moment you should be able to reconnect to the database and
repeat your command.
WARNING: terminating connection because of crash of another server process

I'm out of ideas how to go further in debugging that issue - any
ideas(maybe from somebody who knows windows better than I do) ?

Stefan