fix

Author: marcoieni

src/ci/docker/run.sh

@@ -113,7 +113,7 @@ if [ -f "$docker_dir/$image/Dockerfile" ]; then
     # In this way, we run the SCRIPT defined in CI,
     # instead of the one defined in the Dockerfile.
     if [ -n "${SCRIPT+x}" ]; then
-      build_args="${build_args} --build-arg SCRIPT_ARG=\"${SCRIPT}\""
+      build_args="${build_args} --build-arg \"SCRIPT_ARG=${SCRIPT}\""
     fi
 
     # On non-CI jobs, we try to download a pre-built image from the rust-lang-ci