fix: OK, try the gcc image, see if that will do it

.drone.yml

@@ -30,7 +30,7 @@ steps:
       - mkdir -p lib
       - curl -o lib/sunshine.jar -L 'http://artifacts.metaborg.org/service/local/artifact/maven/redirect?r=snapshots&g=org.metaborg&a=org.metaborg.sunshine2&v=LATEST'
   - name: setup_gen
-    image: silkeh/clang
+    image: gcc
     volumes:
       - name: m2
         path: /root/.m2