repochecker: Use SetWriteFileFunc to avoid writing any file on disk

repochecker/null.go

@@ -0,0 +1,11 @@
+package main
+
+type nullFileWriter struct{}
+
+func (fw *nullFileWriter) Write(p []byte) (int, error) {
+	return len(p), nil
+}
+
+func (fw *nullFileWriter) Close() error {
+	return nil
+}