@Joulinar
Here is the content from the log file
DKMS make.log for wireguard-1.0.20200506 for kernel 4.9.0-9-amd64 (x86_64)
Di 19. Mai 19:45:22 BST 2020
make: Verzeichnis „/usr/src/linux-headers-4.9.0-9-amd64“ wird betreten
LD /var/lib/dkms/wireguard/1.0.20200506/build/built-in.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/main.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/noise.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/device.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/peer.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/timers.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/queueing.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/send.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/receive.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/socket.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/peerlookup.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/allowedips.o
CC [M] /var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.o
/var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.c:25:8: error: unknown type name ‘hsiphash_key_t’
static hsiphash_key_t key;
^~~~~~~~~~~~~~
/var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.c: In function ‘wg_ratelimiter_allow’:
/var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.c:109:22: error: implicit declaration of function ‘hsiphash_2u32’ [-Werror=implicit-function-declaration]
bucket = &table_v4[hsiphash_2u32(net_word, ip, &key) &
^~~~~~~~~~~~~
/var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.c:116:22: error: implicit declaration of function ‘hsiphash_3u32’ [-Werror=implicit-function-declaration]
bucket = &table_v6[hsiphash_3u32(net_word, ip >> 32, ip, &key) &
^~~~~~~~~~~~~
cc1: some warnings being treated as errors
/usr/src/linux-headers-4.9.0-9-common/scripts/Makefile.build:309: die Regel für Ziel „/var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.o“ scheiterte
make[3]: *** [/var/lib/dkms/wireguard/1.0.20200506/build/ratelimiter.o] Fehler 1
/usr/src/linux-headers-4.9.0-9-common/Makefile

die Regel für Ziel „_module_/var/lib/dkms/wireguard/1.0.20200506/build“ scheiterte
make[2]: *** [_module_/var/lib/dkms/wireguard/1.0.20200506/build] Fehler 2
Makefile:152: die Regel für Ziel „sub-make“ scheiterte
make[1]: *** [sub-make] Fehler 2
Makefile:8: die Regel für Ziel „all“ scheiterte
make: *** [all] Fehler 2
make: Verzeichnis „/usr/src/linux-headers-4.9.0-9-amd64“ wird verlassen