This repo explains a problem related to goapp. The problem is that you cannot have multiple
packages that are testable and depend on each other in the same github repo. The reason is because
goapp test sets $GOPATH to the directory of the *_test.go as it runs the test, which means
that importing local package that were originally in $GOPATH during goapp serve are no longer
in the $GOPATH and you get an import error.
# serve runs fine
$ goapp serve .
...
# test breaks
$ goapp test .
main.go:5:2: cannot find package "bar" in any of:
/Users/mgbelisle/gae/go_appengine/goroot/src/pkg/bar (from $GOROOT)
/Users/mgbelisle/go/src/bar (from $GOPATH)
$ goapp test ./bar/
# test breaks on the individual packages too
bar/bar.go:3:8: cannot find package "foo" in any of:
/Users/mgbelisle/gae/go_appengine/goroot/src/pkg/foo (from $GOROOT)
/Users/mgbelisle/go/src/foo (from $GOPATH)
The same problem is described here. The solution is to use one repo per package.