[Debian-mobcom-maintainers] Bug#1100050: osmocom-dahdi-dkms: install fails because of uninterpreted #MODULE_VERSION# in dkms.conf

[Agathe Porte]

Package: osmocom-dahdi-dkms
Version: 0.0~git20241003.b2ea348-3
Severity: grave
Justification: renders package unusable
X-Debbugs-Cc: gagath at debian.org

Dear Maintainer,

When trying to install the osmocom-dahdi-dkms package on unstable, the
build of the modules fail. This is because the dkms.conf file in not
located in the correct location. The #MODULE_VERSION# string not being
interpreted by dh_dkms:

	$ dpkg -L osmocom-dahdi-dkms
	/.
	/usr
	/usr/share
	/usr/share/doc
	/usr/share/doc/osmocom-dahdi-dkms
	/usr/share/doc/osmocom-dahdi-dkms/LICENSE.firmware
	/usr/share/doc/osmocom-dahdi-dkms/README
	/usr/share/doc/osmocom-dahdi-dkms/changelog.Debian.gz
	/usr/share/doc/osmocom-dahdi-dkms/copyright
	/usr/src
	/usr/src/osmocom-dahdi-#MODULE_VERSION#
	/usr/src/osmocom-dahdi-#MODULE_VERSION#/dkms.conf
	/usr/src/osmocom-dahdi-0.0~git20241003.b2ea348
	/usr/src/osmocom-dahdi-0.0~git20241003.b2ea348/Makefile
	...

This regression seems to be coming from this commit in the salsa
repository of the source package:

	commit 2b4c1196b441237bb30a469494379076d2980ee5
	Author: Andreas Beckmann <anbe at debian.org>
	Date:   Sat Feb 8 00:02:10 2025 +0100

		simplify debian/rules

	...

	diff --git a/debian/rules b/debian/rules
	index 3382d61..b46c561 100755
	--- a/debian/rules
	+++ b/debian/rules
	@@ -5,28 +5,11 @@

	 include /usr/share/dpkg/pkg-info.mk

	-export DEB_BUILD_MAINT_OPTIONS = hardening=+all
	-
	 %:
	-       dh $@ --with autoreconf
	-
	-# Don't want to build. Just send source code to
	-# package to be built by DKMS
	-override_dh_auto_build:
	+       dh $@ --buildsystem none

	...

Switching to the "none" buildsystem seems to prevent dh_dkms from being
run, even if it Build-Depends on dh-sequence-dkms.

One simple solution to this problem that I have experimented locally is
to pass the "--with dkms" option to dh in the debian/rules file:

	diff --git c/debian/rules i/debian/rules
	index b46c561..991f6f0 100755
	--- c/debian/rules
	+++ i/debian/rules
	@@ -6,7 +6,7 @@
	 include /usr/share/dpkg/pkg-info.mk

	 %:
	-       dh $@ --buildsystem none
	+       dh $@ --buildsystem none --with dkms

Since "dh-sequence-dkms" is broken for this usecase, maybe the
Build-Depends should also be switched from "dh-sequence-dkms" to
"dh-dkms" if it is accepted.

After applying this patch the dkms.conf file is correctly located with
the source files in ./usr/src/osmocom-dahdi-0.0~git20241003.b2ea348/,
showing that dh_dkms was able to substitute the value correctly.

I will attach a patch to this bug, as well as create a merge request on
the salsa repository, as soon as I get back the bug number from the BTS.

Thanks.