This isn't all that important, and it breaks on musl just because the message is different.
Just skip it for now, until we figure out how to better test this.
Some more of the invocations are tested in this change:
- bad switches
- errors in configuration files
- regular command, configuration and init command ordering
- persistence of variables over command invocation.
- interactive and login switch use
- terminal exit code return
- version request
There are sure to be other invocations that should be tested, but
these give a fair number of them a go.