Bug#912552: gringo ftbfs with Python 3.7

[Matthias Klose]

Package: src:gringo
Version: 5.2.3-2
Severity: serious
Tags: sid buster

gringo ftbfs with Python 3.7:

STDERR:
*** Warn : (clingo): Oversubscription: #Threads=8 exceeds logical CPUs=4.
*** ERROR: (clingo):
/<<PKGBUILDDIR>>/app/clingo/tests/python/interrupt.lp:1:1-15:6: error: error
executing python code:
    File "</<<PKGBUILDDIR>>/app/clingo/tests/python/interrupt.lp:1:1-15:6>", line 11
      with prg.solve(async=True) as handle:
                         ^
  SyntaxError: invalid syntax