The CI did not report any issues with this patch, but maybe an riscv64 test is missing...
Either we exclude these community-ports of Debian, or we simply just apply the patches for the architectures we support and we know it works (like armhf, arm64).

Even if this is just a performance thing, in layers with dozens of packages the overhead of just installing the compilers is huge.
It also bloats the upper-dir of the schroot leading to significant disk consumption.

Jan recently reported that the build time raised a lot when switching an arm64 layer to from ISAR v0.9 to ISAR-next (sbuild).
Very likely most of that came from the crossbuild-essential packages.

Felix

Hello Felix,

I've just checked mc:qemuriscv64-sid-ports:isar-image-base target manually and
it fails with:

| E: Unable to locate package crossbuild-essential-riscv64

on do_rootfs_install task of sbuild-chroot-host recipe, which was predictable.
It was not failed on CI because of KFAIL on Sid-Ports targets (they are not
stable enough).

Overall preinstalling is good idea and will improve building speed, but we
should implement it in the right way.