Re: gmake and ccache conspiring together in creating gremlins

[Edward Welbourne]

Paul Smith (8 February 2021 20:38) wrote:
> There is a loss of debugging information if we make this change: today
> make can detect if it was invoked in a way that _should_ expect to
> receive a jobserver context, but _didn't_ receive that context.  That
> is, if make sees that jobserver-auth is set but it can't open the
> jobserver pipes it can warn the user that most likely there's a
> problem in their environment or with the setup of their makefiles.

Rather than removing the jobserver-auth data, you could amend the
MAKEFLAGS to includ jobserver-auth data with plainly invalid fds,
e.g. -1, as the two fds, to make clear that we're in a context where
jobserver-auth could beneficially have been propagated but wasn't.  The
main thing is just to *not* claim that file descriptors you've closed
are available to access as the jobserver.  That doesn't preclude leaving
it evident to [grand-)*children that this has happened,

        Eddy.