bp0

Sorry I did not provide enough info. I am using Debian bookworm, completely updated as far as I know, and it looks like you might be using Ubuntu. Maybe I needed to use bookworm-backports as you suggested; it looks like a newer version there. I've actually found another way to do what I was trying to do with v4l2loopback and don't need it anymore, but thanks for looking at it. Here is some output that you asked for: _ _ _ /_\ _ _ _ __ | |__(_)__ _ _ _ / _ \| '_| ' \| '_ \ / _` | ' \ /_/ \_\_| |_|_|_|_.__/_\__,_|_||_| v25.5.1 for Renegade running Armbian Linux 6.12.32-current-rockchip64 Packages: Debian stable (bookworm) IPv4: (LAN) 10.0.44.17, 192.168.4.254 (WAN) 107.77.207.5 Performance: Load: 50% Up time: 0 min Memory usage: 13% of 968M CPU temp: 36°C Usage of /: 13% of 30G Commands: Configuration : armbian-config Monitoring : htop Last login: Sat Jul 5 20:21:20 2025 from 10.0.44.1 pburt@gato:~$ cat /etc/debian_version 12.11 pburt@gato:~$ apt-cache policy v4l2loopback-dkms v4l2loopback-dkms: Installed: (none) Candidate: 0.12.7-2 Version table: 0.13.2-1~bpo12+1 100 100 http://deb.debian.org/debian bookworm-backports/main arm64 Packages 100 http://deb.debian.org/debian bookworm-backports/main armhf Packages 0.12.7-2 500 500 http://deb.debian.org/debian bookworm/main arm64 Packages 500 http://deb.debian.org/debian bookworm/main armhf Packages pburt@gato:~$ sudo apt install v4l2loopback-dkms [sudo] password for pburt: Reading package lists... Done Building dependency tree... Done Reading state information... Done The following additional packages will be installed: dkms Suggested packages: menu Recommended packages: fakeroot The following NEW packages will be installed: dkms v4l2loopback-dkms 0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. Need to get 86.0 kB of archives. After this operation, 308 kB of additional disk space will be used. Do you want to continue? [Y/n] Get:1 http://deb.debian.org/debian bookworm/main arm64 dkms all 3.0.10-8+deb12u1 [48.7 kB] Get:2 http://deb.debian.org/debian bookworm/main arm64 v4l2loopback-dkms all 0.12.7-2 [37.2 kB] Fetched 86.0 kB in 1s (119 kB/s) Selecting previously unselected package dkms. (Reading database ... 71668 files and directories currently installed.) Preparing to unpack .../dkms_3.0.10-8+deb12u1_all.deb ... Unpacking dkms (3.0.10-8+deb12u1) ... Selecting previously unselected package v4l2loopback-dkms. Preparing to unpack .../v4l2loopback-dkms_0.12.7-2_all.deb ... Unpacking v4l2loopback-dkms (0.12.7-2) ... Setting up dkms (3.0.10-8+deb12u1) ... Setting up v4l2loopback-dkms (0.12.7-2) ... Loading new v4l2loopback-0.12.7 DKMS files... Building for 6.12.32-current-rockchip64 Building initial module for 6.12.32-current-rockchip64 Error! Bad return status for module build on kernel: 6.12.32-current-rockchip64 (aarch64) Consult /var/lib/dkms/v4l2loopback/0.12.7/build/make.log for more information. dpkg: error processing package v4l2loopback-dkms (--configure): installed v4l2loopback-dkms package post-installation script subprocess returned error exit status 10 Errors were encountered while processing: v4l2loopback-dkms E: Sub-process /usr/bin/dpkg returned an error code (1) pburt@gato:~$ cat /var/lib/dkms/v4l2loopback/0.12.7/build/make.log DKMS make.log for v4l2loopback-0.12.7 for kernel 6.12.32-current-rockchip64 (aarch64) Sun Jul 6 06:20:57 PM CDT 2025 Building v4l2-loopback driver... make -C /lib/modules/6.12.32-current-rockchip64/build M=/var/lib/dkms/v4l2loopback/0.12.7/build modules make[1]: Entering directory '/usr/src/linux-headers-6.12.32-current-rockchip64' CC [M] /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c: In function ‘vidioc_querycap’: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c:717:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strncpy’? [-Werror=implicit-function-declaration] 717 | strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver)); | ^~~~~~~ | strncpy cc1: some warnings being treated as errors make[3]: *** [scripts/Makefile.build:229: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o] Error 1 make[2]: *** [/usr/src/linux-headers-6.12.32-current-rockchip64/Makefile:1945: /var/lib/dkms/v4l2loopback/0.12.7/build] Error 2 make[1]: *** [Makefile:224: __sub-make] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-6.12.32-current-rockchip64' make: *** [Makefile:43: v4l2loopback.ko] Error 2 pburt@gato:~$

v4l2loopback-dkms 0.12.7-2 fails to build make.log: DKMS make.log for v4l2loopback-0.12.7 for kernel 6.12.32-current-rockchip64 (aarch64) Sat Jul 5 09:16:17 PM CDT 2025 Building v4l2-loopback driver... make -C /lib/modules/6.12.32-current-rockchip64/build M=/var/lib/dkms/v4l2loopback/0.12.7/build modules make[1]: Entering directory '/usr/src/linux-headers-6.12.32-current-rockchip64' CC [M] /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c: In function ‘vidioc_querycap’: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c:717:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strncpy’? [-Werror=implicit-function-declaration] 717 | strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver)); | ^~~~~~~ | strncpy cc1: some warnings being treated as errors make[3]: *** [scripts/Makefile.build:229: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o] Error 1 make[2]: *** [/usr/src/linux-headers-6.12.32-current-rockchip64/Makefile:1945: /var/lib/dkms/v4l2loopback/0.12.7/build] Error 2 make[1]: *** [Makefile:224: __sub-make] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-6.12.32-current-rockchip64' make: *** [Makefile:43: v4l2loopback.ko] Error 2 Edit: I had the wrong make.log contents. The old one was after I tried to fix it and failing. The actual build error is missing strlcpy().