:/usr/lib/modules/5.12.9-1-default # ll
total 0
lrwxrwxrwx 1 root root 50 Jun  3 23:57 build ->
../../../usr/src/linux-5.12.9-1-obj/x86_64/default
lrwxrwxrwx 1 root root 31 Jun  3 23:57 source ->
../../../usr/src/linux-5.12.9-1

:/usr/lib/modules/5.12.9-1-default # ll source
lrwxrwxrwx 1 root root 31 Jun  3 23:57 source ->
../../../usr/src/linux-5.12.9-1

:/usr/lib/modules/5.12.9-1-default # cd ../../../usr/src/linux-5.12.9-1
bash: cd: ../../../usr/src/linux-5.12.9-1: No such file or directory

Due to this nvidia driver build fails now in TW. :-(

For now I workarounded the issue in the build.

+%if 0%{?suse_version} >= 1550
+    src=/usr/src/linux-$(make %{?jobs:-j%jobs} -siC %{kernel_source $flavor}
kernelrelease | cut -d "-" -f 1,2)
+%else
     src=/lib/modules/$(make %{?jobs:-j%jobs} -siC %{kernel_source $flavor}
kernelrelease)/source
+%endif
     rm -rf obj/$flavor
     cp -r source obj/$flavor
     make %{?jobs:-j%jobs} -C /usr/src/linux-obj/%_target_cpu/$flavor modules
M=$PWD/obj/$flavor/%{version} SYSSRC="$src"
SYSOUT=/usr/src/linux-obj/%_target_cpu/$flavor
@@ -215,7 +219,11 @@
 export INSTALL_MOD_PATH=%{buildroot}
 export INSTALL_MOD_DIR=updates
 for flavor in %flavors_to_build; do
+%if 0%{?suse_version} >= 1550
+    export SYSSRC=/usr/src/linux-$(make %{?jobs:-j%jobs} -siC %{kernel_source
$flavor} kernelrelease | cut -d "-" -f 1,2)
+%else
     export SYSSRC=/lib/modules/$(make %{?jobs:-j%jobs} -siC %{kernel_source
$flavor} kernelrelease)/source
+%endif
     make %{?jobs:-j%jobs} -C /usr/src/linux-obj/%_target_cpu/$flavor
modules_install M=$PWD/obj/$flavor/%{version}
     #install -m 644 $PWD/obj/$flavor/%{version}/{nv-linux.o,nv-kernel.o} \
     #  %{buildroot}/lib/modules/*-$flavor/updates