Arvados

Starting from scratch by running arvbox directly out of an arvados clone at 78a6558918c:

./arvbox rebuild dev
./arvbox reboot dev

During the boot process, that reports:

/var/lib/arvados/lib/ruby/gems/2.7.0/gems/bundler-2.3.25/lib/bundler/source/git.rb:214:in `rescue in load_spec_files': https://github.com/arvados/nulldb is not yet checked out. Run `bundle install` first. (Bundler::GitError)

This error is apparently nonfatal but it looks very scary (it comes with a huge backtrace) so it's easy for a new developer to think something is wrong.