Hi,

GNU Make now has a --shuffle option that simulates non-deterministic ordering
of target prerequisites. See
https://trofi.github.io/posts/238-new-make-shuffle-mode.html and also previous
work in Debian by Santiago Vila:
https://people.debian.org/~sanvila/make-shuffle/

This package fails to build with make --shuffle=reverse.
This is likely to be caused by a missing dependency in
debian/rules or an upstream Makefile.

More information about this mass bug filing is available at
https://wiki.debian.org/qa.debian.org/FTBFS/Shuffle

Relevant part (hopefully):
The full build log is available from:
http://qa-logs.debian.net/2025/05/05/shuffle/reverse/splint_3.1.2+dfsg-5_unstable_reverse.log

If you reassign this bug to another package, please mark it as 'affects'-ing
this package. See https://www.debian.org/Bugs/server-control#affects

control: tags -1 patch

It looks like you can fix this by adding to src/Makefile.am

mapping.o: Headers/flag_codes.gen

(untested, other than it fixes the build)