Re: should assigning to .SHELLFLAGS suppress fast path?

[Paul Smith]

On Wed, 2015-02-11 at 10:44 -0800, David Boyce wrote:
> I just noticed that while assigning to SHELL suppresses the fast-path
> algorithm, assigning to .SHELLFLAGS does not. Feature or bug?

That's a good question.  I'm sort of agnostic on it.  On one hand, it's
hard to think of a flag added to SHELLFLAGS (given the default value of
SHELL) that would matter for the fast path: we only choose the fast path
if the command is so simple we don't need a shell anyway so flags like
-e, etc. have no relevance.

Of course, there's -x which is perhaps what you were thinking of.
Probably it does make sense to skip the fast path if SHELLFLAGS is not
the default value.