Do not use AssertionError for control flow

When running in optimized mode, asserts are a noop (https://docs.python.org/3/reference/simple_stmts.html#the-assert-statement). We don't use optimized mode in the nightlies, but apparently it happens on the GRID (where the PYTHONOPTIMIZE environment variable is set), and since except AssertionError was used in one place for control flow, that lead to a different behaviour on the GRID.

tl;dr do not catch asserts in Python

added lhcb-head label

added Configuration bug fix labels

This should resolve the issue reported on lhcb-distributed-analysis by @shunan

• [2021-04-18 00:08] Validation started with lhcb-head#2919
• [2021-04-19 00:18] Validation started with lhcb-head#2920

approved this merge request

Ouch.

Good catch!

merged

mentioned in commit d15c95a3

unassigned @rmatev

mentioned in issue #272 (closed)