Hi,
This build's fine for me on a fresh bullseye install:
apt source nginx
cd nginx-1.18.0/
apt build-dep .
time debuild
The latest Salsa version is in a MR:
https://salsa.debian.org/nginx-team/nginx/-/merge_requests/92
(and still in need of a merge! ;))
The package was rebuilt from source before upload too:
https://buildd.debian.org/status/package.php?suite=bullseye-security&p=nginx
so there's probably something wrong in your setup.
You can try to locate the first make *** error for clues, or compare
with the above build logs.
Cheers!
Sylvain Beucler
Debian LTS Team
