QEMU build error for SNP kernel

[mmisono]

$ inv build.build-qemu-snp
$ nix build --out-link /scratch/atsushi/CVM_eval/build/qemu-amd-sev-snp --json .#qemu-amd-sev-snp
error: builder for '/nix/store/kc0hl7dr5lxjlvj7hmwbwjkk3isc19bx-source.drv' failed with exit code 1;
       last 25 log lines:
       > remote: Compressing objects: 100% (2/2), done.
       > remote: Total 2 (delta 0), reused 2 (delta 0), pack-reused 0 (from 0)
       > Unpacking objects: 100% (2/2), 931 bytes | 931.00 KiB/s, done.
       > From https://gitlab.com/qemu-project/vbootrom
       >  * branch            0c37a43527f0ee2b9584e7fb2fdc805e902635ac -> FETCH_HEAD
       > Submodule path 'roms/vbootrom': checked out '0c37a43527f0ee2b9584e7fb2fdc805e902635ac'
       > remote: Total 0 (delta 0), reused 0 (delta 0), pack-reused 0 (from 0)
       > remote: Enumerating objects: 269, done.
       > remote: Counting objects: 100% (269/269), done.
       > remote: Compressing objects: 100% (136/136), done.
       > remote: Total 167 (delta 86), reused 54 (delta 5), pack-reused 0 (from 0)
       > Receiving objects: 100% (167/167), 29.21 KiB | 29.21 MiB/s, done.
       > Resolving deltas: 100% (86/86), completed with 65 local objects.
       > From https://gitlab.com/libvirt/libvirt-ci
       >  * branch            77c800186f34b21be7660750577cc5582a914deb -> FETCH_HEAD
       > Submodule path 'tests/lcitool/libvirt-ci': checked out '77c800186f34b21be7660750577cc5582a914deb'
       > Cloning into '/nix/store/2g178cazqargsbn9f5h55cqiiw7xi8qp-source/roms/edk2/UnitTestFrameworkPkg/Library/SubhookLib/subhook'...
       > fatal: could not read Username for 'https://github.com': No such device or address
       > fatal: clone of 'https://github.com/Zeex/subhook.git' into submodule path
[...]

It seems the submodule URL has changed:
https://github.com/tianocore/edk2/blob/2839fed575f0eccae7f5a89f7252487dd058b462/.gitmodules#L28C8-L28C53

[mmisono]

The workaround is to manually build software.

QEMU

• for 6.8 kernel (see doc for software version)

nix develop nixpkgs#qemu
git clone https://github.com/mmisono/qemu --recursive
cd qemu
git checkout -b snp-latest-20240221 origin/snp-latest-20240221
git submodule update --init
cd ./roms/edk2

• Edit .gitmodules and update the URL

--- a/.gitmodules
+++ b/.gitmodules
@@ -25,7 +25,7 @@
        url = https://github.com/google/googletest.git
 [submodule "UnitTestFrameworkPkg/Library/SubhookLib/subhook"]
        path = UnitTestFrameworkPkg/Library/SubhookLib/subhook
-       url = https://github.com/Zeex/subhook.git
+       url = https://github.com/tianocore/edk2-subhook.git
 [submodule "MdePkg/Library/BaseFdtLib/libfdt"]
        path = MdePkg/Library/BaseFdtLib/libfdt
        url = https://github.com/devicetree-org/pylibfdt.git

# back to the root of the qemu directory
cd ../../
mkdir build
cd build
../configure --target-list=x86_64-softmmu --disable-docs
make -j$(nproc)

# in the CVM_eval directory, create simlink to the built qemu
mkdir -p build/qemu-amd-sev-snp/bin
ln -s <path/to>/qemu-system-x86_64 build/qemu-amd-sev-snp/bin

[mmisono]

I confirmed the current 6.8 and 6.9 have this issue (probably any older version as well). The newer version will not have this issue as the submodule URL is updated.