I have been trying to build the kernel for the past few days and I keep getting errors and its driving me crazy !!!
I follow Qubes Builder | Qubes OS to a tee but I always get errors.

Is it because of this ?
The qubes builder is broken at the moment because of some signing issues with rpms ?
Such a headache for a linux newbie (sorta) like me 
I am trying to build the kernel just for normal 4.0.4, i just want my backlit keyboard to work.
It’s not 4.1
That issue mentions a workaround:
Building for R4.0 would still have the same issue for the following reason:
By the way, how did you manage to get around the SELinux error?
@Qurious Thank you for the reply.
I didn’t seem to experience the SELinux error you mentioned, maybe because i am using and trying to build 4.0.4 and not 4.1 ?
I just tried updating fedora to 33 and trying again.
With fedora 33 I did not get any errors when using “make get-sources”
However I got LOTS of errors afterwards when using “make linux-kernel”
Here are some of the errors.
[user@personal qubes-builder]$ make linux-kernel
-> Retrieving core RPM packages...
Invalid configuration value: failovermethod=priority in /tmp/tmp.zEYWAX8dP9; Configuration: OptionBinding with id "failovermethod" does not exist
Invalid configuration value: failovermethod=priority in /tmp/tmp.zEYWAX8dP9; Configuration: OptionBinding with id "failovermethod" does not exist
-> Installing package groups...Unable to detect release version (use '--releasever' to specify release version)
-> Building linux-kernel (kernel.spec) for fc32 dom0 (logfile: build-logs/linux-kernel-dom0-fc32.log)
--> build failed!
Qubes OS Builder Repository 2.9 MB/s | 3.0 kB 00:00
Qubes OS Builder Repository 24 kB/s | 257 B 00:00
Fedora 32 - x86_64 63 kB/s | 25 kB 00:00
Fedora 32 openh264 (From Cisco) - x86_64 3.2 kB/s | 989 B 00:00
Fedora 32 - x86_64 - Updates 59 kB/s | 24 kB 00:00
Dependencies resolved.
Nothing to do.
Complete!
No matching package to install: 'qubes-kernel-vm-support'
Not all dependencies satisfied
Error: Some packages could not be found.
make[2]: *** [/home/user/qubes-builder/qubes-src/builder-rpm/Makefile-legacy.rpmbuilder:51: dist-build-dep.spec] Error 1
make[2]: Leaving directory '/home/user/qubes-builder'
make[1]: *** [Makefile.generic:191: packages] Error 1
make[1]: Leaving directory '/home/user/qubes-builder'
make: *** [Makefile:267: linux-kernel-dom0] Error 1
[user@personal qubes-builder]$