The long name causes problems with some shells.
Does the LLDB API output a clear and actionable error code if the
filename you are launching is too long?
Nope, it'll try to launch the inferior, and it'll think the inferior ran
and exited with an error code.
If not please add a test for this
I don't think this is testable, it's completely dependent on the shell,
your choice of working directory, and whatever extra arguments there are.