bug#30820: Chunked store references in compiled code break grafting (again)

[Mark H Weaver]

I just realized that my proposal is unworkable.  If we allow strings
containing store paths to be split into pieces, then some of those
pieces may contain as little as one character of the hash.  For example,
the grafter might find "/store/c", which is likely not enough to
determine which of the transitive inputs is being referenced, and
therefore the grafter cannot decide what to write in place of the "c".

Sorry for the noise.

       Mark