checkNumberOfBondedInteractions not exiting on failure
Using DD, the system is checked for missing bonded interactions. This check should exit on a fatal error if it fails. In this check, however, there is a global summation that is enclosed within a logging statement that is only executed on master rank. This will cause master to wait for the other ranks indefinitely, and prevents the program to terminate.
The bug was introduced in https://gerrit.gromacs.org/q/I6d39dc41d23fe3e0ed8ee51d326c8d2264112b1f (merged Sep 11, 2018), meaning that the affected versions are likely 2019 and 2020. Going through the change, it doesn't seem that any other similar problems were introduced.
Fix checkNumberOfBondedInteractions bug
When checkNumberOfBondedInteractions finds a missing interaction, the
program is not exiting because a function enclosed in a logging statement
starts a global reduction, but is only ever reached by master.