What if another placeholder which hasn't been replaced yet precedes the ${walltime:? msg.index('}') would return an index which is before msg.index('${walltime:').

Ok, you're right. Line:

time_format = msg[msg.index('${walltime:') + len('${walltime:'): msg.index('}')]

should looks like

tag_end_index = msg.index('${walltime:') + len('${walltime:')
time_format = msg[tag_end_index: msg.index('}', tag_end_index)]

I'll fix it by next week.

@dirk-thomas I added unit test for formatted timestamp, but there are some problems on Npr_* builds. Could you tell me what does Npr_ stands for?

These are the PR builds for the upcoming ROS Noetic distribution.

Just recently the default branch of this repo has moved to noetic-devel so please retarget that branch instead (and then the already existing Mpr results won't be updated anymore).

Is there a problem with a Jenkins pipeline script on line git rev-parse origin/noetic-devel^{commit} ?

12:00:50  > git rev-parse origin/noetic-devel^{commit} # timeout=10
12:00:50 FATAL: Command "git rev-parse origin/noetic-devel^{commit}" returned status code 128:
12:00:50 stdout: origin/noetic-devel^{commit}
12:00:50 
12:00:50 stderr: fatal: ambiguous argument 'origin/noetic-devel^{commit}': unknown revision or path not in the working tree.

[Npr__ros_comm__ubuntu_focal_amd64/138/]

I even tried an another PR-draft on #1892, made the same error: FATAL: Command "git rev-parse origin/noetic-devel^{commit}" returned status code 128: [Npr__ros_comm__ubuntu_focal_amd64/139]