This small exercise illustrates issues with go vendoring experiment and nested vendor folders.
Comparison of two equal values (from human point of view)
xxx.A == yyy.A
will not even compile because of mismatched types.
Check this out:
GO15VENDOREXPERIMENT=1 go get github.com/coxx/try-go-vendoring
This issue is discussed in detail in Dave Cheney's talk "Reproducible Builds".