use expr

.cirrus.yml

@@ -26,8 +26,8 @@ env:
   SKIP_DOCTEST_TASK: ""
   SKIP_LINKCHECK_TASK: ""
   # Skip task groups by type.
-  SKIP_ALL_TEST_TASKS: ""
-  SKIP_ALL_DOC_TASKS: ""
+  SKIP_ALL_TEST_TASKS: "true"
+  SKIP_ALL_DOC_TASKS: "true"
   # Maximum cache period (in weeks) before forcing a new cache upload.
   CACHE_PERIOD: "2"
   # Increment the build number to force new cartopy cache upload.
@@ -100,7 +100,7 @@ lint_task:
     folder: ~/.cache/pip
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
+      - echo "$(date +%Y).$(expr $(date +%U) / ${CACHE_PERIOD}):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
   lint_script:
     - pip list
     - python -m pip install --retries 3 --upgrade ${PIP_CACHE_PACKAGES}