Use a docker volume to preserve state

Author: alecbcs

.github/workflows/outputs.yml

@@ -42,9 +42,9 @@ jobs:
 
     - name: Re-generate outputs from tutorial scripts
       run: |
+        docker volume create spack
+        DOCKER_RUN_OPTS="-e COLUMNS=94 -e COLIFY_SIZE=24x94 -v spack:/home/spack/spack"
         chmod -R a+w outputs
-        mkdir shared-spack && chmod -R a+rwx shared-spack
-        DOCKER_RUN_OPTS="-e COLUMNS=94 -e COLIFY_SIZE=24x94 -v $(pwd)/shared-spack:/home/spack/spack"
         make -C outputs -j $(nproc) DOCKER_RUN_OPTS="$DOCKER_RUN_OPTS" container=ghcr.io/spack/tutorial
 
     - name: Show diff of modified files