Cache failed blocks new jobs

.gitlab-ci.yml

@@ -61,13 +61,11 @@ spack:setup:
     - SPACK_VERSION=$(jq -r .spack.version config.json)
 
     - |
-      if [ ! -d spack ]; then
+      if [ ! -d spack/.git ]; then
         git clone https://github.com/spack/spack.git -b $SPACK_VERSION spack
       else
-        cd spack
-        git fetch
-        git checkout $SPACK_VERSION
-        cd -
+        git -C spack fetch
+        git -C spack checkout $SPACK_VERSION
       fi
 
     - spack/bin/spack gpg trust $GPG_PRIVATE_KEY
@@ -86,10 +84,8 @@ spack:setup:
           url_branch=$(jq -r ".spack.repos.\"${repo}\".url" config.json)
           git clone -b ${repo_branch} ${url_branch} /stack/extra_repos/$repo
         else
-          cd /stack/extra_repos/$repo
-          git fetch
-          git checkout ${repo_branch}
-          cd -
+          git -C /stack/extra_repos/$repo fetch
+          git -C /stack/extra_repos/$repo checkout ${repo_branch}
         fi
       done