Bem localizada, a página de manual está incorreta. debuild --help
mostra a sintaxe apropriada:
--dpkg-buildpackage-hook=HOOK
--clean-hook=HOOK
--dpkg-source-hook=HOOK
--build-hook=HOOK
--binary-hook=HOOK
--dpkg-genchanges-hook=HOOK
--final-clean-hook=HOOK
--lintian-hook=HOOK
--signing-hook=HOOK
--post-dpkg-buildpackage-hook=HOOK
These hooks run at the various stages of the
dpkg-buildpackage run. For details, see the
debuild manpage. They default to nothing, and
can be reset to nothing with --foo-hook=''
Então, o seu exemplo seria
debuild --signing-hook=/signing-hook-script.sh -i -S
( debuild
opções devem ser especificadas antes das opções dpkg-buildpackage
).