currently out of date as of September 2022, needs a fresh update
TLDR; edit the amdgpu-install script to add pop as supported debian distribution, comment out check for linux-modules-extra-[versions] since they're provided by linux-modules [per Jeremy Solle of System_76], then run with --no-dkms
3 EDIT: 4 things need to be done.
Problem 1) Pop!_OS not valid install target "Unsupported OS: /etc/os-release ID 'pop'" The issue as of now is that amdgpu-install doesnt recognize pop as a valid installation candidate. Solution is to add pop as a valid target in the amdgpu-install script.
As of Dec 1 2021: change line 241 to include
| pop
Pop!_OS will then be seen as a valid installation target
Problem 2) No linux-modules-extra package available
Package linux-modules-extra-5.15.5-76051505-generic is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'linux-modules-extra-5.15.5-76051505-generic' has no installation candidate
Pop!_OS includes what would normally be in linux modules extra in the standard linux-modules package, then marks linux-modules-extra as a virtual package [see https://twitter.com/jeremy_soller/status/1466061665548390402?s=20]
Solution is to remove the check by commenting out lines 360-363 Edit:the lines may have moved depending on version. You're loocking for the lines referencing linux-modules-extra
Problem 3) DPKG error kernel package not supported
ERROR (dkms apport): kernel package linux-headers-5.15.5-76051505-generic is not supported
Error! Bad return status for module build on kernel: 5.15.5-76051505-generic (amd64)
Consult /var/lib/dkms/amdgpu/5.11.32-1337797/build/make.log for more information.
dpkg: error processing package amdgpu-dkms (--configure):
installed amdgpu-dkms package post-installation script subprocess returned error exit status 10
Errors were encountered while processing:
amdgpu-dkms
E: Sub-process /usr/bin/dpkg returned an error code (1)
DKMS isnt needed, we're better off using the in kernel module already provided
Solution is to use the --no-dkms flag at install time
EDIT:2022/03/24
Problem 4) With the move from Hirsute to Impish, some repositories are no longer available and will cause the building of rocm-llvm to fail. The missing packages on a near vanilla instalation are: python-six, libgcc-5 series and libgcc-7 series.
As of now the best way to deal with this is to add the legacy LTS repositories from 18.04 LTS which have all missing packages to our apt sources and proceed that way.
Edit /etc/apt/sources.list and add the line
deb http://mirrors.kernel.org/ubuntu bionic main universe
sudo apt update
Then run the command as before with the relevant options.
As always this isnt fully sanctioned and supported by AMD or System76 (creators and maintaners of Pop!_OS) but being as this is downstream Debian/Ubuntu you shouldn't run into any issues. No guarentees, but it seems fine on my end.