The result of a MAKE attempt:
sudo make KERNELRELEASE=4.9.35-v7+ -C /lib/modules/4.9.35-v7+/build M=/var/lib/dkms/seeed-voicecard/0.3/build
make: Entering directory ‘/usr/src/linux-headers-4.9.35-v7+’
CC [M] /var/lib/dkms/seeed-voicecard/0.3/build/wm8960.o
In file included from /var/lib/dkms/seeed-voicecard/0.3/build/wm8960.c:28:0:
/var/lib/dkms/seeed-voicecard/0.3/build/sound-compatible-4.18.h:19:5: warning: “__has_attribute” is not defined [-Wundef]
#if __has_attribute(fallthrough)
^
/var/lib/dkms/seeed-voicecard/0.3/build/sound-compatible-4.18.h:19:20: error: missing binary operator before token “(”
#if __has_attribute(fallthrough)
^
scripts/Makefile.build:293: recipe for target ‘/var/lib/dkms/seeed-voicecard/0.3/build/wm8960.o’ failed
make[1]: *** [/var/lib/dkms/seeed-voicecard/0.3/build/wm8960.o] Error 1
Makefile:1490: recipe for target ‘module/var/lib/dkms/seeed-voicecard/0.3/build’ failed
make: *** [module/var/lib/dkms/seeed-voicecard/0.3/build] Error 2
make: Leaving directory ‘/usr/src/linux-headers-4.9.35-v7+’
Obviously there’s an issue with the __has_attribute method, but I’m not sure how to resolve this without really getting into the weeds.