Junio C Hamano <gitster@xxxxxxxxx> writes:
> Can't you route the control upon seeing "git difftool" to your
> experimental "C" difftool and check the configuration there? Then
> you can decide to run_command() a non-builtin one depending what the
> configuration says---that way, you would incur cost of spawning Perl
> only when you need it, no?
FWIW, the approach taken by 73c2779f42 ("builtin-am: implement
skeletal builtin am", 2015-08-04) is what I had in mind when I wrote
the above.