Comment # 28 on bug 1173733 from Stefan Dirsch

(In reply to Mister Pend from comment #25)
> Created attachment 839480 [details]
> sample files from two machines
> 
> sample files from two machines, one working one not

You're using different NVreg_DeviceFileGID on your machines (not using our
default of 33). Also on the broken machine
/usr/lib/tmpfiles.d/nvidia-logind-acl-trick.conf is missing completely.

# diff -u -r prodmachine\ \(broken\)/ testmachine\ \(works\)/
diff -u -r "prodmachine (broken)/etc/modprobe.d/50-nvidia-default.conf"
"testmachine (works)/etc/modprobe.d/50-nvidia-default.conf"
--- "prodmachine (broken)/etc/modprobe.d/50-nvidia-default.conf"       
2020-07-08 11:22:44.000000000 +0200
+++ "testmachine (works)/etc/modprobe.d/50-nvidia-default.conf" 2020-07-08
11:23:42.000000000 +0200
@@ -1,2 +1,2 @@
-options nvidia NVreg_DeviceFileUID=0 NVreg_DeviceFileGID=483
NVreg_DeviceFileMode=0660
+options nvidia NVreg_DeviceFileUID=0 NVreg_DeviceFileGID=484
NVreg_DeviceFileMode=0660
 install nvidia PATH=$PATH:/bin:/usr/bin; if /sbin/modprobe --ignore-install
nvidia; then   if /sbin/modprobe nvidia_uvm; then     if [ ! -c /dev/nvidia-uvm
]; then       mknod -m 660 /dev/nvidia-uvm c $(cat /proc/devices | while read
major device; do if [ "$device" == "nvidia-uvm" ]; then echo $major; break; fi
; done) 0;        chown :video /dev/nvidia-uvm;     fi;   fi;   if [ ! -c
/dev/nvidiactl ]; then     mknod -m 660 /dev/nvidiactl c 195 255;     chown
:video /dev/nvidiactl;   fi;   devid=-1;   for dev in $(ls -d
/sys/bus/pci/devices/*); do      vendorid=$(cat $dev/vendor);     if [
"$vendorid" == "0x10de" ]; then       class=$(cat $dev/class);      
classid=${class%%00};       if [ "$classid" == "0x0300" -o "$classid" ==
"0x0302" ]; then          devid=$((devid+1));         if [ ! -c
/dev/nvidia${devid} ]; then            mknod -m 660 /dev/nvidia${devid} c 195
${devid};            chown :video /dev/nvidia${devid};         fi;       fi;   
 fi;   done;   /sbin/modprobe nvidia_drm;   if [ ! -c /dev/nvidia-modeset ];
then     mknod -m 660 /dev/nvidia-modeset c 195 254;     chown :video
/dev/nvidia-modeset;   fi; fi 
\ No newline at end of file
Only in testmachine (works)/usr/lib/tmpfiles.d: nvidia-logind-acl-trick.conf