debuild stops parsing its own options at the first argument it does not recognise and hands the rest to dpkg-buildpackage. `-d` is such an argument, so --no-lintian was forwarded and rejected:
dpkg-buildpackage: error: unknown option or argument --no-lintian
debuild turned that into a `die`, which exits with errno when it is non-zero - ENOTTY (25) on a Jenkins agent with no tty - so the nightly failed with the fairly opaque `exit status 25`.
