still can't get past rename/ParseIface

[Malcolm Wallace]

Ok, someone suggested I downgrade from happy-1.10 to happy-1.9, which
I did.  The build continued to fail at rename/ParseIface.hs for the
same reason.  So I removed that file, thinking that the build process
would be able to rebuild it via rename/ParseIface.y, using Happy.
But no joy - Happy is not found.  The error message is:

> RTS -K2m -H16m -RTS  -g    rename/ParseIface.y
> make[2]: RTS: Command not found
> make[2]: *** [rename/ParseIface.hs] Error 127

Obviously the configuration process has failed to fill in a variable
somewhere with the path to Happy.  I've tried 'make clean' and
'make distclean' and re-configuring, but to no avail.  (In fact,
'make clean' fails part-way through, in the hood subdir with "No rule
to make target `clean'".)  No matter what I do, configure seems to
use cached information rather than recalculating version numbers etc.
It still seems to think I've got Happy 1.10 in the tree rather than
1.9.  I don't know how to tell it otherwise.

Where do I go from here?
Regards,
    Malcolm