[Bug go/78912] New: Relative import when compiling with `go build` is not resolved

[jdanek at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78912

            Bug ID: 78912
           Summary: Relative import when compiling with `go build` is not
                    resolved
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: jdanek at redhat dot com
                CC: cmang at google dot com
  Target Milestone: ---

Created attachment 40410
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40410&action=edit
reproducer_project.zip

The attached project compiles with go tool

$ go version
go version go1.7.3 linux/amd64
$ GOPATH=`pwd` go build electron/broker.go
$ ./broker
Print from broker.go
Print from util.go

It does not compile with gccgo (I am running gcc in Docker)

$ docker run -v `pwd`:/mnt --rm -it jdanekrh/nightly-gccgo-trunk-docker-image
root@d454c37d5d3e:/# cd /mnt
root@d454c37d5d3e:/mnt# go version
go version go1.7.1 gccgo (GCC) 7.0.0 20161223 (experimental) linux/amd64
root@d454c37d5d3e:/mnt# GOPATH=`pwd` go build electron/broker.go
# command-line-arguments
electron/broker.go:4:12: error: import file '../util' not found
     "../util"
            ^
electron/broker.go:10:5: error: reference to undefined name 'util'
     util.PrintSomething()

I have tried setting the -fgo-relative-import-path option, (GOPATH=`pwd` go
build -gccgoflags -fgo-relative-import-path=`pwd`/electron electron/broker.go)
but I could not make it work that way either.

This bug may be similar to https://github.com/golang/go/issues/3759. The
reproducer from that bug compiles fine for me (relative import in that
reproducer starts ./, not ../ like in this case).