bug#74699: need valid explanation / weird 'grep -q' behaviour

[Paul Eggert]

On 2024-12-04 15:43, Frank Reppin wrote:
> Some claim that this is due to 'set -o pipefail' beeing used in the 
> script... but this does not really explain why it only _sometimes_ happens.

I don't see why not. Pipe buffering is an "it all depends" situation.

Anyway, I tried your script on bleeding-edge grep on Fedora 40 and it 
worked fine for me. You didn't mention your grep version; behavior in 
this area changed in 2016, though I doubt your version is that old.

One workaround is to use "set -o pipefail" only for pipelines where you 
want the entire pipeline to fail merely because one component failed.