diff --git a/Makefile b/Makefile
index 83fd6a1..9e01077 100644
--- a/Makefile
+++ b/Makefile
@@ -85,6 +85,9 @@ generate: ttrpc
 
 ttrpc:
 	go mod download
+	ls -l ${GOPATH}/pkg/mod/
+	ls -l ${GOPATH}/pkg/mod/github.com
+	ls -l ${GOPATH}/pkg/mod/github.com/prometheus
 	cd api/shim/v1; protoc --go_out=. --go_opt=paths=source_relative \
 	--ttrpc_out=. --plugin=protoc-gen-ttrpc=`which protoc-gen-go-ttrpc` \
 	--ttrpc_opt=paths=source_relative *.proto -I. \