Comment 6 for bug 2015801

I would like to upvote this bug. Having broken source package in Bionic is less than ideal.

I am not sure there is a technical reason for grub2 to depend on gcc-10. Debian package follows build-deps from the target codeline so that's probably not a right argument here. For example,
grub 2.06 in Buster still depends on gcc-8: https://salsa.debian.org/grub-team/grub/-/blob/buster/debian/control

Bionic toolchain should be perfectly capable of compiling grub. I tried to build grub2-unsigned-2.06 on Bionic after dropping gcc-10 and fuse3 dependency. It builds, tests pass, and amd64 binaries appear to work on the live system. Please consider publishing grub2-unsigned with correct dependencies for the codeline regardless of how the binary packages are produced and published.