Potential place the migrator should error out

[nex3]

A user on twitter has reported a case where the migrator takes valid Sass and produces what seems to be invalid Sass. @jathak can you investigate? I think this might be because it used to be loading stuff into the global scope which it's not anymore.

[jathak]

Yeah, it looks like Bootstrap 3 assumes that its stylesheets are imported in a shared scope in a particular order, so it's not possible to just @use particular files.

Catching this is tricky, since we need to somehow detect when a stylesheet that is being migrated depends on stylesheets that aren't being migrated in an order-dependent way.

[nex3]

Could we combine the existing logic for detecting if a member is being used from a scope it can't import with the logic for detecting if a member needs to be renamed in an un-migrated dependency?