900e83b5 changed from a warning
to an error in this case, but the warning was only issued in
verbose mode, and therefore the error was only raised in verbose
mode.  That was not intentional, verbose mode should only change
whether warnings are emitted, not other behavior.  This issues
the RuntimeError in all cases.

This change broke a couple tests, as the tests actually issued
the warning and therefore now raise an error.  This wasn't caught
earlier as test_variable suppressed the warning in this case,
effectively setting $VERBOSE = false around the code that warned.
basictest isn't run in verbose mode and therefore didn't expose
the issue previously. Fix these tests.

Fixes [Bug #14541]