How to visualize code coverage information on Go GAE apps?

There is an open issue related to it. As a temporary workaround, I am running sed in between collecting and visualizing the coverage results.

goapp test -cover -test.v=true -test.coverprofile=c.out
sed -i -e "s#.*/\(.*\.go\)#\./\\1#" c.out
goapp tool cover -html c.out -o coverage.html