@ralsina , Hi, you need add backed_file_system as dependency in your shard.
BTW: do you consider update tartrazine’s backed_file_system dependency to use original shard?
Error shard name (baked_file_system) has ambiguous sources:
'git: https://github.com/schovi/baked_file_system.git' and
'git: https://github.com/ralsina/baked_file_system.git'.
I guess you need update the shard.yml for both sixteen and tartrazine.