show cache miss diff

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

Taskfile.yaml

@@ -11,7 +11,7 @@ vars:
   TMP_DIR: .tmp
   ORAS_CACHE: "{{ .TMP_DIR }}/oras-cache"
   CACHE_PATHS_FILE: "{{ .TMP_DIR }}/cache_paths.json"
-  LAST_CACHE_PULL_FILE: "{{ .TMP_DIR }}/last_cache_pull"
+  LAST_CACHE_PULL_FILE: "{{ .TMP_DIR }}/last_cache_paths.json"
 
   # TOOLS
   ORAS: "{{ .TOOL_DIR }}/oras"
@@ -335,7 +335,7 @@ tasks:
       echo "desired cache:     $WANT_FINGERPRINT"
       
       if [ -f {{ .LAST_CACHE_PULL_FILE }} ]; then
-        LAST_PULL_FINGERPRINT=$(cat {{ .LAST_CACHE_PULL_FILE }})
+        LAST_PULL_FINGERPRINT=$(cat {{ .LAST_CACHE_PULL_FILE }} | {{ .YQ }} -r '.digest')
       else
         echo -e "${BOLD}${PURPLE}empty cache, refreshing cache...${RESET}"
         {{ .TASK }} clean-cache download-test-fixture-cache
@@ -360,6 +360,11 @@ tasks:
         {{ .TASK }} clean-cache download-test-fixture-cache
       else
         echo -e "${BOLD}${PURPLE}found newer cache, but does not match what we want (skipping cache refresh)${RESET}"
+      
+        {{ .YQ }} eval '.paths[] | "\(.digest) \(.path)"' {{ .LAST_CACHE_PULL_FILE }} > .tmp/last_cache_lines
+        {{ .YQ }} eval '.paths[] | "\(.digest) \(.path)"' {{ .CACHE_PATHS_FILE }} > .tmp/cache_lines
+        diff .tmp/last_cache_lines .tmp/cache_lines
+      
       fi
 
   build-fixtures:
@@ -389,7 +394,7 @@ tasks:
         sh: docker manifest inspect {{ .CACHE_IMAGE }} | jq -r '.annotations.fingerprint'
     cmds:
       - "ORAS_CACHE={{ .ORAS_CACHE }} {{ .ORAS }} pull {{ .CACHE_IMAGE }}"
-      - "echo '{{ .CACHE_DIGEST }}' > {{ .LAST_CACHE_PULL_FILE }}"
+      - "cp {{ .CACHE_PATHS_FILE }} {{ .LAST_CACHE_PULL_FILE }}"
 
   upload-test-fixture-cache:
     desc: Upload the test fixture cache to ghcr.io