From 23542e567abceafb3b19e381327dc674243284ab Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sat, 20 Feb 2021 22:25:41 +0000
Subject: [PATCH 1/7] cirrus-ci conditional tasks

---
 .cirrus.yml                                   | 30 ++++++++---
 docs/src/common_links.inc                     |  1 +
 .../contributing_ci_tests.rst                 | 53 +++++++++++++++----
 .../contributing_code_formatting.rst          |  2 -
 docs/src/whatsnew/latest.rst                  |  4 ++
 5 files changed, 70 insertions(+), 20 deletions(-)

diff --git a/.cirrus.yml b/.cirrus.yml
index 3f9e45b5ea..98bd2b7e7b 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -18,6 +18,16 @@ container:
 
 
 env:
+  # Skip specific tasks by name.
+  SKIP_LINT_TASK: ""
+  SKIP_TEST_MINIMAL_TASK: ""
+  SKIP_TEST_FULL_TASK: ""
+  SKIP_GALLERY_TASK: ""
+  SKIP_DOCTEST_TASK: ""
+  SKIP_LINKCHECK_TASK: ""
+  # Skip task groups by type.
+  SKIP_ALL_TEST_TASKS: ""
+  SKIP_ALL_DOC_TASKS: ""
   # Maximum cache period (in weeks) before forcing a new cache upload.
   CACHE_PERIOD: "2"
   # Increment the build number to force new cartopy cache upload.
@@ -50,7 +60,7 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     fingerprint_script:
       - wget --quiet https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh
       - echo "${CIRRUS_OS} $(sha256sum miniconda.sh)"
-      - echo "$(date +%Y).$(($(date +%U) / ${CACHE_PERIOD})):${CONDA_CACHE_BUILD}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CONDA_CACHE_BUILD}"
     populate_script:
       - bash miniconda.sh -b -p ${HOME}/miniconda
       - conda config --set always_yes yes --set changeps1 no
@@ -62,12 +72,12 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     folder: ${HOME}/.local/share/cartopy
     fingerprint_script:
       - echo "${CIRRUS_OS}"
-      - echo "$(date +%Y).$(($(date +%U) / ${CACHE_PERIOD})):${CARTOPY_CACHE_BUILD}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CARTOPY_CACHE_BUILD}"
   nox_cache:
     folder: ${CIRRUS_WORKING_DIR}/.nox
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(($(date +%U) / ${CACHE_PERIOD})):${NOX_CACHE_BUILD}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${NOX_CACHE_BUILD}"
       - sha256sum ${CIRRUS_WORKING_DIR}/requirements/ci/py$(echo ${PY_VER} | tr -d ".").yml
 
 
@@ -82,6 +92,7 @@ compute_credits_template: &CREDITS_TEMPLATE
 # Linting
 #
 lint_task:
+  only_if: $SKIP_LINT_TASK == ""
   << : *CREDITS_TEMPLATE
   auto_cancellation: true
   name: "${CIRRUS_OS}: flake8 and black"
@@ -89,7 +100,7 @@ lint_task:
     folder: ~/.cache/pip
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(($(date +%U) / ${CACHE_PERIOD})):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
   lint_script:
     - pip list
     - python -m pip install --retries 3 --upgrade ${PIP_CACHE_PACKAGES}
@@ -101,7 +112,8 @@ lint_task:
 #
 # Testing Minimal (Linux)
 #
-linux_minimal_task:
+test_minimal_task:
+  only_if: $SKIP_TEST_MINIMAL_TASK == "" && $SKIP_ALL_TEST_TASKS == ""
   << : *CREDITS_TEMPLATE
   matrix:
     env:
@@ -125,7 +137,8 @@ linux_minimal_task:
 #
 # Testing Full (Linux)
 #
-linux_task:
+test_full_task:
+  only_if: $SKIP_TEST_FULL_TASK == "" && $SKIP_ALL_TEST_TASKS == ""
   << : *CREDITS_TEMPLATE
   matrix:
     env:
@@ -159,6 +172,7 @@ linux_task:
 # Testing Documentation Gallery (Linux)
 #
 gallery_task:
+  only_if: $SKIP_GALLERY_TASK == "" && $SKIP_ALL_DOC_TASKS == ""
   << : *CREDITS_TEMPLATE
   matrix:
     env:
@@ -188,6 +202,7 @@ gallery_task:
 # Testing Documentation (Linux)
 #
 doctest_task:
+  only_if: $SKIP_DOCTEST_TASK == "" && $SKIP_ALL_DOC_TASKS == ""
   << : *CREDITS_TEMPLATE
   matrix:
     env:
@@ -222,7 +237,8 @@ doctest_task:
 #
 # Testing Documentation Link Check (Linux)
 #
-link_task:
+linkcheck_task:
+  only_if: $SKIP_LINKCHECK_TASK == "" && $SKIP_ALL_DOC_TASKS == ""
   << : *CREDITS_TEMPLATE
   matrix:
     env:
diff --git a/docs/src/common_links.inc b/docs/src/common_links.inc
index 23a933367e..d9df15be8b 100644
--- a/docs/src/common_links.inc
+++ b/docs/src/common_links.inc
@@ -3,6 +3,7 @@
 
 .. _black: https://black.readthedocs.io/en/stable/
 .. _.cirrus.yml: https://github.com/SciTools/iris/blob/master/.cirrus.yml
+.. _flake8: https://flake8.pycqa.org/en/stable/
 .. _.flake8.yml: https://github.com/SciTools/iris/blob/master/.flake8
 .. _cirrus-ci: https://cirrus-ci.com/github/SciTools/iris
 .. _conda: https://docs.conda.io/en/latest/
diff --git a/docs/src/developers_guide/contributing_ci_tests.rst b/docs/src/developers_guide/contributing_ci_tests.rst
index a6bdac4ae0..d50e712d54 100644
--- a/docs/src/developers_guide/contributing_ci_tests.rst
+++ b/docs/src/developers_guide/contributing_ci_tests.rst
@@ -28,19 +28,46 @@ please see https://scitools.org.uk/organisation.html#governance
 Cirrus-CI
 *********
 
-The unit and integration tests in Iris are an essential mechanism to ensure
+Iris unit and integration tests are an essential mechanism to ensure
 that the Iris code base is working as expected.  :ref:`developer_running_tests`
-may be run manually but to ensure the checks are performed a
-continuous integration testing tool named `cirrus-ci`_ is used.
+may be performed manually by a developer locally. However Iris is configured to
+use the `cirrus-ci`_ service for automated Continuous Integration (CI) testing.
 
-A `cirrus-ci`_ configuration file named `.cirrus.yml`_
-is in the Iris repository which tells Cirrus-CI what commands to run.  The
-commands include retrieving the Iris code base and associated test files using
-conda and then running the tests.  `cirrus-ci`_ allows for a matrix of tests to
-be performed to ensure that all expected variations test successfully.
+The `cirrus-ci`_ configuration file  `.cirrus.yml`_ in the root of the Iris repository
+defines the tasks to be performed by `cirrus-ci`_. For further details
+refer to the `Cirrus-CI Documentation`_. The tasks performed during CI include:
+
+* linting the code base and ensuring it adheres to the `black`_ format
+* running the system, integration and unit tests for Iris
+* ensuring the documentation gallery builds successfully
+* performing all doc-tests within the code base
+* checking all URL references within the code base and documentation are valid
+
+The above `cirrus-ci`_ tasks are run automatically against all `Iris`_ branches
+on GitHub whenever a pull request is submitted, updated or merged. See the
+`Cirrus-CI Dashboard`_ for details of recent past and active Iris jobs.
+
+.. _skipping Cirrus-CI tasks:
+
+Skipping Cirrus-CI Tasks
+------------------------
+
+As a developer you may not wish to run all the CI tasks when you are actively
+developing e.g., you are writing documentation and there is no need for linting,
+or long running compute intensive testing tasks to be executed.
+
+As a convenience, it is possible to easily skip one or more tasks by setting
+the appropriate environment variable within the `.cirrus.yml`_ file:
+
+* ``SKIP_LINT_TASK`` to skip `flake8`_ linting and `black`_ formatting
+* ``SKIP_TEST_MINIMAL_TASK`` to skip restricted unit and integration testing
+* ``SKIP_TEST_FULL_TASK`` to skip full unit and integration testing
+* ``SKIP_GALLERY_TASK`` to skip building the documentation gallery
+* ``SKIP_DOCTEST_TASK`` to skip running the documentation doc-tests
+* ``SKIP_LINKCHECK_TASK`` to skip checking for broken documentation URL references
+* ``SKIP_ALL_TEST_TASKS`` which is equivalent to setting ``SKIP_TEST_MINIMAL_TASK`` and ``SKIP_TEST_FULL_TASK``
+* ``SKIP_ALL_DOC_TASKS`` which is equivalent to setting ``SKIP_GALLERY_TASK``, ``SKIP_DOCTEST_TASK``, and ``SKIP_LINKCHECK_TASK``
 
-The `cirrus-ci`_ tests are run automatically against the `Iris`_ master
-repository when a pull request is submitted, updated or merged.
 
 GitHub Checklist
 ****************
@@ -50,6 +77,10 @@ passing:
 
 .. image:: ci_checks.png
 
-If any CI checks fail, then the pull request is unlikely to be merged to the
+If any CI tasks fail, then the pull request is unlikely to be merged to the
 Iris target branch by a core developer.
 
+
+.. _Cirrus-CI Dashboard: https://cirrus-ci.com/github/SciTools/iris
+.. _Cirrus-CI Documentation: https://cirrus-ci.org/guide/writing-tasks/
+
diff --git a/docs/src/developers_guide/contributing_code_formatting.rst b/docs/src/developers_guide/contributing_code_formatting.rst
index 6bf8dca717..1a3573d135 100644
--- a/docs/src/developers_guide/contributing_code_formatting.rst
+++ b/docs/src/developers_guide/contributing_code_formatting.rst
@@ -58,6 +58,4 @@ will look similar to::
           their officially documentation for more information.
 
 
-.. _black: https://black.readthedocs.io/en/stable/
-.. _flake8: https://flake8.pycqa.org/en/stable/
 .. _pre-commit: https://pre-commit.com/
diff --git a/docs/src/whatsnew/latest.rst b/docs/src/whatsnew/latest.rst
index 59e75942b0..9c967c3279 100644
--- a/docs/src/whatsnew/latest.rst
+++ b/docs/src/whatsnew/latest.rst
@@ -124,6 +124,10 @@ This document explains the changes made to Iris for this release
 #. `@akuhnregnier`_ replaced `deprecated numpy 1.20 aliases for builtin types`_.
    (:pull:`3997`)
 
+#. `@bjlittle`_ added conditional task execution to `.cirrus.yml`_ to allow
+   developers to easily disable `cirrus-ci`_ tasks. See
+   :ref:`skipping Cirrus-CI tasks`. (:pull:`4018`)
+
 
 .. comment
     Whatsnew author names (@github name) in alphabetical order. Note that,

From f758b8f9920fc6a899a7747a630ee510e2b793a2 Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sun, 21 Feb 2021 10:14:15 +0000
Subject: [PATCH 2/7] use bc for bash arithmetic

---
 .cirrus.yml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/.cirrus.yml b/.cirrus.yml
index 98bd2b7e7b..13e5108c03 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -60,7 +60,7 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     fingerprint_script:
       - wget --quiet https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh
       - echo "${CIRRUS_OS} $(sha256sum miniconda.sh)"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CONDA_CACHE_BUILD}"
+      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${CONDA_CACHE_BUILD}"
     populate_script:
       - bash miniconda.sh -b -p ${HOME}/miniconda
       - conda config --set always_yes yes --set changeps1 no
@@ -72,12 +72,12 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     folder: ${HOME}/.local/share/cartopy
     fingerprint_script:
       - echo "${CIRRUS_OS}"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CARTOPY_CACHE_BUILD}"
+      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${CARTOPY_CACHE_BUILD}"
   nox_cache:
     folder: ${CIRRUS_WORKING_DIR}/.nox
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${NOX_CACHE_BUILD}"
+      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${NOX_CACHE_BUILD}"
       - sha256sum ${CIRRUS_WORKING_DIR}/requirements/ci/py$(echo ${PY_VER} | tr -d ".").yml
 
 
@@ -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).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
   lint_script:
     - pip list
     - python -m pip install --retries 3 --upgrade ${PIP_CACHE_PACKAGES}

From f0b7d80d48d5c974189711f22cd355339911ea62 Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sun, 21 Feb 2021 10:20:20 +0000
Subject: [PATCH 3/7] revert back to sed

---
 .cirrus.yml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/.cirrus.yml b/.cirrus.yml
index 13e5108c03..98bd2b7e7b 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -60,7 +60,7 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     fingerprint_script:
       - wget --quiet https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh
       - echo "${CIRRUS_OS} $(sha256sum miniconda.sh)"
-      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${CONDA_CACHE_BUILD}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CONDA_CACHE_BUILD}"
     populate_script:
       - bash miniconda.sh -b -p ${HOME}/miniconda
       - conda config --set always_yes yes --set changeps1 no
@@ -72,12 +72,12 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     folder: ${HOME}/.local/share/cartopy
     fingerprint_script:
       - echo "${CIRRUS_OS}"
-      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${CARTOPY_CACHE_BUILD}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CARTOPY_CACHE_BUILD}"
   nox_cache:
     folder: ${CIRRUS_WORKING_DIR}/.nox
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${NOX_CACHE_BUILD}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${NOX_CACHE_BUILD}"
       - sha256sum ${CIRRUS_WORKING_DIR}/requirements/ci/py$(echo ${PY_VER} | tr -d ".").yml
 
 
@@ -100,7 +100,7 @@ lint_task:
     folder: ~/.cache/pip
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(echo $(date +%U) / ${CACHE_PERIOD} | bc):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
+      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${PIP_CACHE_BUILD} ${PIP_CACHE_PACKAGES}"
   lint_script:
     - pip list
     - python -m pip install --retries 3 --upgrade ${PIP_CACHE_PACKAGES}

From 9600ec3e6d3442e666f3d66ac97b4c05deefbd3a Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sun, 21 Feb 2021 10:28:44 +0000
Subject: [PATCH 4/7] use expr

---
 .cirrus.yml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/.cirrus.yml b/.cirrus.yml
index 98bd2b7e7b..7fc0db468c 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -60,7 +60,7 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     fingerprint_script:
       - wget --quiet https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh
       - echo "${CIRRUS_OS} $(sha256sum miniconda.sh)"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CONDA_CACHE_BUILD}"
+      - echo "$(date +%Y).$(expr $(date +%U) / ${CACHE_PERIOD}):${CONDA_CACHE_BUILD}"
     populate_script:
       - bash miniconda.sh -b -p ${HOME}/miniconda
       - conda config --set always_yes yes --set changeps1 no
@@ -72,12 +72,12 @@ linux_task_template: &LINUX_TASK_TEMPLATE
     folder: ${HOME}/.local/share/cartopy
     fingerprint_script:
       - echo "${CIRRUS_OS}"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${CARTOPY_CACHE_BUILD}"
+      - echo "$(date +%Y).$(expr $(date +%U) / ${CACHE_PERIOD}):${CARTOPY_CACHE_BUILD}"
   nox_cache:
     folder: ${CIRRUS_WORKING_DIR}/.nox
     fingerprint_script:
       - echo "${CIRRUS_TASK_NAME}"
-      - echo "$(date +%Y).$(($(echo $(date +%U) | sed 's/^0*//') / ${CACHE_PERIOD})):${NOX_CACHE_BUILD}"
+      - echo "$(date +%Y).$(expr $(date +%U) / ${CACHE_PERIOD}):${NOX_CACHE_BUILD}"
       - sha256sum ${CIRRUS_WORKING_DIR}/requirements/ci/py$(echo ${PY_VER} | tr -d ".").yml
 
 
@@ -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}

From 0dfc55b342b8c64a753823f05ea652e8576d437a Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sun, 21 Feb 2021 11:42:36 +0000
Subject: [PATCH 5/7] reword

---
 docs/src/developers_guide/contributing_ci_tests.rst | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/docs/src/developers_guide/contributing_ci_tests.rst b/docs/src/developers_guide/contributing_ci_tests.rst
index d50e712d54..2320d0cf51 100644
--- a/docs/src/developers_guide/contributing_ci_tests.rst
+++ b/docs/src/developers_guide/contributing_ci_tests.rst
@@ -52,12 +52,13 @@ on GitHub whenever a pull request is submitted, updated or merged. See the
 Skipping Cirrus-CI Tasks
 ------------------------
 
-As a developer you may not wish to run all the CI tasks when you are actively
+As a developer you may wish to not run all the CI tasks when you are actively
 developing e.g., you are writing documentation and there is no need for linting,
 or long running compute intensive testing tasks to be executed.
 
 As a convenience, it is possible to easily skip one or more tasks by setting
-the appropriate environment variable within the `.cirrus.yml`_ file:
+the appropriate environment variable within the `.cirrus.yml`_ file to a
+non-empty string:
 
 * ``SKIP_LINT_TASK`` to skip `flake8`_ linting and `black`_ formatting
 * ``SKIP_TEST_MINIMAL_TASK`` to skip restricted unit and integration testing
@@ -68,6 +69,14 @@ the appropriate environment variable within the `.cirrus.yml`_ file:
 * ``SKIP_ALL_TEST_TASKS`` which is equivalent to setting ``SKIP_TEST_MINIMAL_TASK`` and ``SKIP_TEST_FULL_TASK``
 * ``SKIP_ALL_DOC_TASKS`` which is equivalent to setting ``SKIP_GALLERY_TASK``, ``SKIP_DOCTEST_TASK``, and ``SKIP_LINKCHECK_TASK``
 
+e.g., to skip the linting task, the following are all equivalent::
+
+   SKIP_LINT_TASK: "1"
+   SKIP_LINT_TASK: "true"
+   SKIP_LINT_TASK: "false"
+   SKIP_LINT_TASK: "skip"
+   SKIP_LINT_TASK: "unicorn"
+
 
 GitHub Checklist
 ****************

From f13ae38d064ba720cc8e64d314b68ed81c36e4fd Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sun, 21 Feb 2021 17:00:02 +0000
Subject: [PATCH 6/7] minor documentation changes

---
 docs/src/developers_guide/contributing_ci_tests.rst | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/docs/src/developers_guide/contributing_ci_tests.rst b/docs/src/developers_guide/contributing_ci_tests.rst
index 2320d0cf51..ace1e55638 100644
--- a/docs/src/developers_guide/contributing_ci_tests.rst
+++ b/docs/src/developers_guide/contributing_ci_tests.rst
@@ -5,9 +5,9 @@
 Continuous Integration (CI) Testing
 ===================================
 
-The `Iris`_ GitHub repository is configured to run checks on the code
-automatically when a pull request is created, updated or merged against
-Iris **master**.  The checks performed are:
+The `Iris`_ GitHub repository is configured to run checks against all its
+branches automatically whenever a pull request is created, updated or merged.
+The checks performed are:
 
 * :ref:`testing_cla`
 * :ref:`testing_cirrus`
@@ -18,9 +18,9 @@ Iris **master**.  The checks performed are:
 SciTools CLA Checker
 ********************
 
-A bot that checks the user who created the pull request has signed the
-**Contributor's License Agreement (CLA)**.  For more information on this this
-please see https://scitools.org.uk/organisation.html#governance
+A bot which checks that the GitHub author of the pull request has signed the
+**SciTools Contributor's License Agreement (CLA)**.  For more information on
+this please see https://scitools.org.uk/organisation.html#governance.
 
 
 .. _testing_cirrus:

From a3c15a354ae86bff178177467ebceefe4c62ad48 Mon Sep 17 00:00:00 2001
From: Bill Little <bill.james.little@gmail.com>
Date: Sun, 21 Feb 2021 17:37:48 +0000
Subject: [PATCH 7/7] review actions

---
 .cirrus.yml                                         | 4 ++--
 docs/src/developers_guide/contributing_ci_tests.rst | 2 +-
 docs/src/whatsnew/latest.rst                        | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/.cirrus.yml b/.cirrus.yml
index 7fc0db468c..0a7c972821 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -18,14 +18,14 @@ container:
 
 
 env:
-  # Skip specific tasks by name.
+  # Skip specific tasks by name. Set to a non-empty string to skip.
   SKIP_LINT_TASK: ""
   SKIP_TEST_MINIMAL_TASK: ""
   SKIP_TEST_FULL_TASK: ""
   SKIP_GALLERY_TASK: ""
   SKIP_DOCTEST_TASK: ""
   SKIP_LINKCHECK_TASK: ""
-  # Skip task groups by type.
+  # Skip task groups by type. Set to a non-empty string to skip.
   SKIP_ALL_TEST_TASKS: ""
   SKIP_ALL_DOC_TASKS: ""
   # Maximum cache period (in weeks) before forcing a new cache upload.
diff --git a/docs/src/developers_guide/contributing_ci_tests.rst b/docs/src/developers_guide/contributing_ci_tests.rst
index ace1e55638..8594612fe1 100644
--- a/docs/src/developers_guide/contributing_ci_tests.rst
+++ b/docs/src/developers_guide/contributing_ci_tests.rst
@@ -58,7 +58,7 @@ or long running compute intensive testing tasks to be executed.
 
 As a convenience, it is possible to easily skip one or more tasks by setting
 the appropriate environment variable within the `.cirrus.yml`_ file to a
-non-empty string:
+**non-empty** string:
 
 * ``SKIP_LINT_TASK`` to skip `flake8`_ linting and `black`_ formatting
 * ``SKIP_TEST_MINIMAL_TASK`` to skip restricted unit and integration testing
diff --git a/docs/src/whatsnew/latest.rst b/docs/src/whatsnew/latest.rst
index 9c967c3279..4abf1e1192 100644
--- a/docs/src/whatsnew/latest.rst
+++ b/docs/src/whatsnew/latest.rst
@@ -126,7 +126,7 @@ This document explains the changes made to Iris for this release
 
 #. `@bjlittle`_ added conditional task execution to `.cirrus.yml`_ to allow
    developers to easily disable `cirrus-ci`_ tasks. See
-   :ref:`skipping Cirrus-CI tasks`. (:pull:`4018`)
+   :ref:`skipping Cirrus-CI tasks`. (:pull:`4019`)
 
 
 .. comment