Update .gitlab-ci.yml

.gitlab-ci.yml

@@ -1,4 +1,16 @@
-image: fpco/stack-build:lts-13.21
+default:
+  image: fpco/stack-build:lts-13.21
+  before_script: |
+    apt-get install -y --no-install-recommends g++
+
+variables:
+  STACK_ROOT: "${CI_PROJECT_DIR}/.stack"
+
+cache:
+  key: "%CI_COMMIT_REF_SLUG"
+  paths:
+    - .stack
+    - .stack-work
 
 build:
   stage: build
@@ -6,8 +18,4 @@ build:
     - stack build --copy-bins --local-bin-path $(pwd) --flag uniworx:-library-only --flag uniworx:-dev --flag uniworx:pedantic
   artifacts:
     paths:
-      - uniworx
-  cache:
-    key: "%CI_COMMIT_REF_SLUG"
-    paths:
-      - .stack-work
+      - uniworx