This bug causes debhelper to discard the actual error message (i.e. the actual reason why the options are invalid).
TL;DR: If your package fails due to debhelper 10.9, please check if you passed invalid/unknown package name to -p / --package or -N / --no-package. This is the single most common reason for an error. To understand when/why this bug triggers, there is an example below based on a concrete error in the source package "webhook": > dh binary --buildsystem=golang --with=golang --with systemd > dh_testroot -O--buildsystem=golang > [...] > dh_systemd_enable -O--buildsystem=golang > debian/rules override_dh_installinit > make[1]: Entering directory '/build/1st/webhook-2.5.0' > dh_systemd_enable -popenstack --name=openstack openstack.service > dh_systemd_enable: unknown option or error during option parsing; aborting > debian/rules:17: recipe for target 'override_dh_installinit' failed The *actual* error message that is hidden here is that the "-popenstack" option, because webhook does not built a binary package called "openstack". To trigger this bug, several things must be present: * There must be an invalid option passed to a helper. This is the -popenstack in the above example. * The helper must also receive a "-O<something>" option via DH_OPTIONS (or DH_INTERNAL_OPTIONS). Often, this triggers via option passed to "dh", which adds it to DH_OPTIONS when invoking override targets. In the concrete example, this is "-O--buildsystem=golang". To "undo" the bug and get the original error message, you can /often/ just unset DH_OPTIONS / DH_INTERNAL_OPTIONS and call the helper with the shown options. Thanks, ~Niels
