diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index fbc066b..c39e374 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -37,6 +37,7 @@ stages:
   script:
     - cargo install cargo-sweep
     - cargo sweep -i
+    - git -C $CI_PROJECT_DIR/.cargo/registry/index/github.com-1ecc6299db9ec823/ gc || true
 
 # this builds a "base" version of fif with default features enabled. this is done separately from the main build step
 # for the purposes of caching - by building once *before* executing the parallel cargo-build step, we ensure that
@@ -59,7 +60,7 @@ stages:
         - multi-threaded infer-backend
 
   script:
-    cargo build --no-default-features --locked --features="json $FEATURES"
+    cargo run --no-default-features --locked --features="json $FEATURES" -- --version
 
 # test with various features on and off.
 .cargo-test: