fix: Check if HEAD of origin/master is accessible from latest tag (#888)

* Fix wheel version check on push events to origin/master on releases
   - Needed to work with Tag Creator workflow (c.f. PR #884)
   - Fixes deployment of releases to TestPyPI as well
   - Amends PR #884

.github/workflows/publish-package.yml

@@ -23,6 +23,7 @@ jobs:
         python-version: 3.7
     - name: Install pep517 and twine
       run: |
+        python -m pip install --upgrade pip setuptools wheel
         python -m pip install pep517 --user
         python -m pip install twine
     - name: Build a binary wheel and a source tarball
@@ -31,12 +32,19 @@ jobs:
     - name: Verify untagged commits have dev versions
       if: "!startsWith(github.ref, 'refs/tags/')"
       run: |
+        latest_tag=$(git describe --tags)
+        latest_tag_revlist_SHA=$(git rev-list -n 1 ${latest_tag})
+        master_SHA="$(git rev-parse --verify origin/master)"
         wheel_name=$(find dist/ -iname "*.whl" -printf "%f\n")
-        if [[ "${wheel_name}" == *"pyhf-0.1.dev"* || "${wheel_name}" != *"dev"* ]]; then
-          echo "pep517.build incorrectly named built distribution: ${wheel_name}"
-          echo "pep517 is lacking the history and tags required to determine version number"
-          echo "intentionally erroring with 'return 1' now"
-          return 1
+        if [[ "${latest_tag_revlist_SHA}" != "${master_SHA}" ]]; then # don't check master push events coming from tags
+          if [[ "${wheel_name}" == *"pyhf-0.1.dev"* || "${wheel_name}" != *"dev"* ]]; then
+            echo "pep517.build incorrectly named built distribution: ${wheel_name}"
+            echo "pep517 is lacking the history and tags required to determine version number"
+            echo "intentionally erroring with 'return 1' now"
+            return 1
+          fi
+        else
+          echo "Push event to origin/master was triggered by push of tag ${latest_tag}"
         fi
         echo "pep517.build named built distribution: ${wheel_name}"
     - name: Verify tagged commits don't have dev versions