oracle: report a better error if query is outside GOROOT/GOPATH
oracle: report a better error if query is outside GOROOT/GOPATH

Change-Id: I2f724b5015021be8bf1fccb518f17cc011d687e8
Reviewed-on: https://go-review.googlesource.com/9546
Reviewed-by: David Chase <ae171625adc8645b8b79b7e405a6da5aba5341e0@google.com>

nicot/tools,jdhenke/tools,argandas/tools,cmars/tools,josharian/tools,matryer/tools,matryer/tools,josharian/tools,nicot/tools,nicot/tools,syreclabs/go-tools,golang/tools,springning/tools,jdhenke/tools,argandas/tools,magiccao/tools,cw2018/tools,glasser/golang-tools,magiccao/tools,jdhenke/tools,sshetty10/tools,syreclabs/go-tools,josharian/tools,cmars/tools,runcom/tools,syreclabs/go-tools,cw2018/tools,josharian/tools,nicot/tools,runcom/tools,cw2018/tools,sshetty10/tools,magiccao/tools,golang/tools,cmars/tools,syreclabs/go-tools,matryer/tools,runcom/tools,jdhenke/tools,sshetty10/tools,syreclabs/go-tools,golang/tools,argandas/tools,golang/tools,cmars/tools,springning/tools,matryer/tools,argandas/tools,runcom/tools,glasser/golang-tools,springning/tools,glasser/golang-tools,sshetty10/tools,cw2018/tools,syreclabs/go-tools,golang/tools,springning/tools,magiccao/tools,glasser/golang-tools