List tests for all systems

[ekouts]

I am not sure how hard it would be to implement but it would be nice if a user could list all the tests that reframe can find for all available systems in the configuration, possibly with some extra information about the system for each test in the output. Now the user would have to run reframe manually for each system:

reframe -c checks -C config.py -L --system=sys1
...
reframe -c checks -C config.py -L --system=sys2
...

Maybe we could add one more cli option to list all tests, not only the current system, -a?

[vkarak]

Have you tried the listing with the --skip-system-check option?

But generally I don't know if this request is going to be easy to implement, because the configuration is loaded per system, so the time reframe loads the configuration, it assumes that it is on as specific system, and this happens very early, before any attempt to load a test.

I understand it's a bit inconvenient to run reframe once per system, but I don't know if it is really worth the fuss.