> -- however I wonder, if sh.exe does not work,
> why does the makefile try to use it? I would have thought sh.exe
> would have been better.
The Windows port of GNU Make always tries to use sh.exe if it sees it
on Path, it always did that. It assumes that your sh.exe port is
fully functional and compatible with the rest of the development
tools, and it knows that a Unixy shell provides more features than
cmd. This has nothing to do with Emacs.
The Emacs Windows configury also tries to find a Unixy shell first,
for the same reasons. For compatible ports of the shell, the Emacs
build does work.
It appears that your sh.exe is somehow incompatible. The file
nt/INSTALL lists combinations of various tools, including the shell,
which are known to build Emacs successfully. Perhaps yours is not one