When async tasks fail, all exceptions need to be collected to not get
subsequent exceptions about invalid future states. This is achieved by
gathering the task results, instead of just waiting for them. By
gathering the results, also user-requested cancellation (e.g. via
ctrl-c) works without throwing tons of additional exceptions.
Since ac437308 we more likely run into that case, which unvealed the bug.
By properly handling the exception, a TaskResultError is returned
instead of the underlying CommandExecError. This change is reflected in
the corresponding unit test.
Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>