lets do it like this

.github/workflows/ci_suite.yml

@@ -65,6 +65,13 @@ jobs:
     name: Lint with OpenDream
     runs-on: ubuntu-20.04
     steps:
+      - name: Restore Yarn cache
+        uses: actions/cache@v3
+        with:
+          path: OpenDream
+          key: ${{ runner.os }}-opendream-${{ hashFiles('dependencies.sh') }}
+          restore-keys: |
+            ${{ runner.os }}-opendream-
       - uses: actions/checkout@v3
       - name: Setup OD
         run: |

dependencies.sh

@@ -19,3 +19,5 @@ export SPACEMAN_DMM_VERSION=suite-1.7.2
 
 # Python version for mapmerge and other tools
 export PYTHON_VERSION=3.7.9
+
+export OPENDREAM_VERSION=0.2.0

tools/ci/setup_od.sh

@@ -1,8 +1,13 @@
 #!/bin/bash
 set -eo pipefail
 
+if [ -z "${OPENDREAM_VERSION+x}" ]; then
+	source dependencies.sh
+fi
+
 git clone https://github.com/OpenDreamProject/OpenDream.git OpenDream
 cd OpenDream
+git checkout tags/v${OPENDREAM_VERSION}
 git submodule update --init --recursive
 dotnet restore
 dotnet build -c Release