The Dependencies component registers itself as completer when the completer would otherwise be null. This causes an infinite loop in Annotate when compiling annotations.

Update: The reason for having a 'while' loop over the completer is to make sure the symbol is pulled through both Enter and MemberEnter. Having 'completer == null' as termination condition is however not compatible with Dependecies (which adds itself as completer when the completer would otherwise be null).