Be sure we delete the dummy tests.

hack/lib/golang.sh

@@ -496,9 +496,10 @@ EOF
 
 # Argument: the name of a Kubernetes package (e.g. k8s.io/kubernetes/cmd/kube-scheduler).
 # Deletes a test generated by kube::golang::create_coverage_dummy_test.
+# It is not an error to call this for a nonexistent test.
 kube::golang::delete_coverage_dummy_test() {
   local package="$1"
-  rm $(kube::golang::path_for_coverage_dummy_test "${package}")
+  rm -f $(kube::golang::path_for_coverage_dummy_test "${package}")
 }
 
 # Arguments: a list of kubernetes packages to build.
@@ -515,14 +516,16 @@ kube::golang::build_some_binaries() {
     for package in "$@"; do
       if kube::golang::is_covered_binary "${package}"; then
         V=2 kube::log::info "Building ${package} with coverage..."
+
         kube::golang::create_coverage_dummy_test "${package}"
+        kube::util::trap_add "kube::golang::delete_coverage_dummy_test \"${package}\"" EXIT
+
         go test -c -o "$(kube::golang::outfile_for_binary "${package}" "${platform}")" \
           -covermode count \
           -coverpkg k8s.io/... \
           "${build_args[@]}" \
           -tags coverage \
           "${package}"
-        kube::golang::delete_coverage_dummy_test "${package}"
       else
         uncovered+=("${package}")
       fi