Can't say why the dirnode doesn't find dump.pike all of a sudden.
Something to watch out for is duplicate dirnode trees however. I have a suspicion that there might be such a problem lurking, because in my own testing yesterday, ENCODE_DEBUG reported several cases like this:
nameof (object Stdio) found program in objects: object_program(Stdio) found path in programs: "/home/mast/Pike/devel/lib/modules/Stdio.pmod/module.pmod" program name: "Stdio" compare_resolved: Stdio is different from Stdio Warning: Failed to resolve; encoding path returned "o/home/mast/Pike/devel/lib/modules/Stdio.pmod/module.pmod"
And having several Stdio modules doesn't look good.
Maybe the replaced master is the culprit there as well, or perhaps it's a problem with all that compat resolver stuff. I have however seen it for Tools.AutoDoc, which doesn't exist in any of the module compat trees.