build: Bail out early if m4 or lex don't exist.
authorAndre Noll <maan@tuebingen.mpg.de>
Sun, 25 Apr 2021 22:04:05 +0000 (00:04 +0200)
committerAndre Noll <maan@tuebingen.mpg.de>
Wed, 28 Apr 2021 21:04:10 +0000 (23:04 +0200)
commit7623e601612eb36cf86511b40fef3f5a20e8b834
tree26f7631d3245bb54dcd0785844fb77da09bcaa64
parentd6f28609ba3b250079ac0c55422dafdabb6c0c71
build: Bail out early if m4 or lex don't exist.

This gives a decent error message on the attempt to run make(1) on a
system where one or both of these essential programs are not installed.

A previous version of the patch used .SHELLSTATUS instead of the
dummy variable, but this did not work with make-4.1 which ships
with Ubuntu-18.04.

Suggested-by: Alex Gietz <oss@mcdinner.de>
Makefile