Fix lazy CI for snapshots

.github/workflows/lazy.yml

@@ -153,6 +153,11 @@ jobs:
     name: Check snapshots (without validation)
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
       - uses: actions-rs/cargo@v1
         name: Test all (without validation)
         with:

tests/in/bits.param.ron

@@ -1,4 +1,5 @@
 (
+	msl_custom: true,
 	msl: (
 		lang_version: (1, 2),
 		per_stage_map: (