github.com/davegardnerisme/deephash is a dependency of moqueries. Apparently Go dependency management is getting hung up on the transitive dependency (transitive to the project generating the mocks). Might be caused by the lack of go.mod in deephash (which has no dependencies other that the standard library).
WORKAROUND
$ go get github.com/davegardnerisme/deephash
Then retry generating the mocks.