Using go 1.6.3 on amd64, I was encountering an error stemming from go-import tags containing a hostname that did not match the import path.

While this stemmed from a misconfiguration of a gitlab instance, it took a bit of time to spot the discrepancy, as the errors coming from go get were generic and gave the (me) impression that no tags were present, as opposed to a mismatch.

This can be reproduced with gitlab (and probably other tools) by attempting to go get the package by using a hostname other than the currently configured external_url.

The current behaviour is to emit a warning like:
package git1.host.com/user/package: unrecognized import path "git1.host.com/user/package" (parse https://git1.host.com/user/package?go-get=1: no go-import meta tags)

I think it would be helpful if the error message gave more context about why no meta tags were matched.
A small patch i've prepared would change the output to:
package git1.host.com/user/package: unrecognized import path "git1.host.com/user/package" (parse https://git1.host.com/user/package?go-get=1: no go-import meta tags (prefix [git.host.com user package] did not match import [git1.host.com user package]))

where the erroneous host from gitlab is git.host.com, failing to match git1.host.com.