Hi,
The wireguard module (0.0.20181119 from Debian Unstable) fails to build on
my machine using kernel 4.20 rc4.

I get the following errors:

# cat /var/lib/dkms/wireguard/0.0.20181119/build/make.log
> DKMS make.log for wireguard-0.0.20181119 for kernel 4.20.0-rc4 (x86_64)
> Sat Dec  1 22:51:18 EET 2018
> make: Entering directory '/usr/src/linux-headers-4.20.0-rc4'
>   CC [M]  /var/lib/dkms/wireguard/0.0.20181119/build/main.o
>   CC [M]  /var/lib/dkms/wireguard/0.0.20181119/build/noise.o
>   CC [M]  /var/lib/dkms/wireguard/0.0.20181119/build/device.o
>   CC [M]  /var/lib/dkms/wireguard/0.0.20181119/build/peer.o
> Assembler messages:
> Error: can't open arch/x86/kernel/macros.s for reading: No such file or
> directory
> make[1]: *** [scripts/Makefile.build:293:
> /var/lib/dkms/wireguard/0.0.20181119/build/main.o] Error 1
> make[1]: *** Waiting for unfinished jobs....
> Assembler messages:
> Error: can't open arch/x86/kernel/macros.s for reading: No such file or
> directory
> ./arch/x86/include/asm/atomic64_64.h:160: Error: no such instruction:
> `lock_prefix xaddq %rax,peer_counter(%rip)'
> ./arch/x86/include/asm/bitops.h:76: Error: no such instruction:
> `lock_prefix orb $32,1592(%rbx)'
> ./arch/x86/include/asm/bitops.h:114: Error: no such instruction:
> `lock_prefix andb $-2,1592(%rbx)'
> ./arch/x86/include/asm/bitops.h:114: Error: no such instruction:
> `lock_prefix andb $-9,1592(%rbx)'
> ./arch/x86/include/asm/jump_label.h:23: Error: no such instruction:
> `static_branch_nop l_yes=".L15"key="descriptor.66338+40"branch="0"'
> ./include/linux/netdevice.h:515: Error: no such instruction: `asm_bug
> ins=".byte 0x0f, 0x0b"file=.LC0 line=515 flags=0 size=12'
> ./include/linux/netdevice.h:515: Error: no such instruction:
> `annotate_unreachable counter=80'
> ./arch/x86/include/asm/atomic.h:200: Error: no such instruction:
> `lock_prefix cmpxchgl %ecx,(%rdx)'
> ./arch/x86/include/asm/refcount.h:109: Error: no such instruction:
> `refcount_error counter="(%rdx)"'
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 1528(%rbx)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="1528(%rbx)"'
> ./arch/x86/include/asm/jump_label.h:23: Error: no such instruction:
> `static_branch_nop l_yes=".L61"key="descriptor.66372+40"branch="0"'
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 1528(%rdi)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="1528(%rdi)"'
> ./arch/x86/include/asm/jump_label.h:23: Error: no such instruction:
> `static_branch_nop l_yes=".L80"key="descriptor.66372+40"branch="0"'
> Assembler messages:
> Error: can't open arch/x86/kernel/macros.s for reading: No such file or
> directory
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 4(%rdi)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="4(%rdi)"'
> ./arch/x86/include/asm/jump_label.h:23: Error: no such instruction:
> `static_branch_nop l_yes=".L6"key="descriptor.67356+40"branch="0"'
> ./arch/x86/include/asm/jump_label.h:23: Error: no such instruction:
> `static_branch_nop l_yes=".L32"key="descriptor.67420+40"branch="0"'
> ./arch/x86/include/asm/refcount.h:65: Error: no such instruction:
> `lock_prefix incl 4(%rdi)'
> ./arch/x86/include/asm/refcount.h:66: Error: no such instruction:
> `refcount_check_lt_zero counter="4(%rdi)"'
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 4(%rdi)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="4(%rdi)"'
> /var/lib/dkms/wireguard/0.0.20181119/build/device.c:404: Error: no such
> instruction: `asm_bug ins=".byte 0x0f, 0x0b"file=.LC7 line=404 flags=2305
> size=12'
> /var/lib/dkms/wireguard/0.0.20181119/build/device.c:404: Error: no such
> instruction: `annotate_reachable counter=163'
> ./arch/x86/include/asm/bitops.h:76: Error: no such instruction:
> `lock_prefix orb $32,328(%rax)'
> make[1]: *** [scripts/Makefile.build:293:
> /var/lib/dkms/wireguard/0.0.20181119/build/peer.o] Error 1
> make[1]: *** [scripts/Makefile.build:293:
> /var/lib/dkms/wireguard/0.0.20181119/build/device.o] Error 1
> Assembler messages:
> Error: can't open arch/x86/kernel/macros.s for reading: No such file or
> directory
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 680(%rbx)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="680(%rbx)"'
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 680(%rbx)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="680(%rbx)"'
> ./arch/x86/include/asm/atomic.h:200: Error: no such instruction:
> `lock_prefix cmpxchgl %ecx,(%rdx)'
> ./arch/x86/include/asm/refcount.h:109: Error: no such instruction:
> `refcount_error counter="(%rdx)"'
> ./arch/x86/include/asm/refcount.h:90: Error: no such instruction:
> `lock_prefix decl 680(%rbx)'
> ./arch/x86/include/asm/refcount.h:91: Error: no such instruction:
> `refcount_check_lt_zero counter="680(%rbx)"'
> ./arch/x86/include/asm/atomic64_64.h:160: Error: no such instruction:
> `lock_prefix xaddq %rax,keypair_counter(%rip)'
> make[1]: *** [scripts/Makefile.build:293:
> /var/lib/dkms/wireguard/0.0.20181119/build/noise.o] Error 1
> make: *** [Makefile:1565:
> _module_/var/lib/dkms/wireguard/0.0.20181119/build] Error 2
> make: Leaving directory '/usr/src/linux-headers-4.20.0-rc4'
>
>