fai-mirror failing due to dependencies

[Laura Smith]

For example:

fai-mirror  /srv/fai/mirror

Fails on grub-pc:


Package grub-pc 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
However the following packages replace it:
  grub2-common grub-common

E: Package 'grub-pc' has no installation candidate
ERROR: 25600 25600
ERROR:  apt-get  -d        -o Aptitude::Log=/dev/null       -o Aptitude::CmdLine::Ignore-Trust-Violations=yes      -o APT::Get::AllowUnauthenticated=true       -o Acquire::AllowInsecureRepositories=true       -o DPkg::force-conflicts::=yes       -o Dir::State=/srv/fai/mirror/aptcache/var/lib/apt       -o Dir::Log=/srv/fai/mirror/aptcache/var/log/apt       -o Dir::State::extended_states=/srv/fai/mirror/aptcache/var/lib/apt/lists/extended_states       -o Dir::State::status=/srv/fai/mirror/aptcache/statefile       -o Dir::Cache=/srv/fai/mirror/aptcache/var/cache/apt       -o Dir::State=/srv/fai/mirror/aptcache/var/cache/apt       -o Dir::Cache::Archives=/srv/fai/mirror/aptcache/var/cache/apt/archives       -o Dir::Etc=/srv/fai/mirror/aptcache/etc/apt/       -o Dir::State::Lists=/srv/fai/mirror/aptcache/var/lib/apt/lists/ -y --fix-missing install --no-install-recommends  grub-pc return code 100
8 errors during executing of install_packages
ERROR when downloading packages. Your mirror is broken. Use fai-mirror -v for details.