`nix-build pkgs/top-level/release.nix -A tarball` now succeeds.
`configureFlags = null` lead to a type error, and one overrideDrv
needed to be converted to to append a configureFlags list instead of
string due to the normalization.
Thanks @vcunat for alerting me to the issues---sorry I did not catch
them before merging my own PR.
Eventually the adapter will be removed. Moved is
- Name suffix from hostPlatform
- configurePlatforms
To not cause more breakage, the default is currently [], but
eventually it will be [ "build" "host" ], as the cross adapter makes
it today.
