This means that you can run just a single case from the command line,
for example:
`qa_pcbnew -t DRCCopperSliver/_0`
The case is also automatically printed as context.
This means that when isolating a specific defect in one case,
you can run only that one case, which is useful under debuggers
and also when using slow tools like valgrind.
Not all possibe tests are doing this, but they're easy to do
when needed (i.e. when you want to run just one case)
This is not only a useful place to hang regression tests,
but also allows to catch defects specific to loading or
saving footprints.
For example, it would catch:
Relates-To: https://gitlab.com/kicad/code/kicad/-/issues/19713
