Fix ensure_sha (jupyter-server#427)

* fix ensure_sha and doc links

* docs

README.md

@@ -30,5 +30,4 @@ GitHub actions scripts are available to draft a changelog, draft a release, publ
 See the [action details documentation](https://jupyter-releaser.readthedocs.io/en/latest/background/theory.html#action-details) for more information.
 
 The actions can be run on a [fork](https://jupyter-releaser.readthedocs.io/en/latest/how_to_guides/convert_repo_from_releaser.html#) of `jupyter_releaser` and target multiple
-repositories, or run as workflows on the [source repositories](https://jupyter-releaser.readthedocs.io/en/latest/how_to_guides/convert_repo_from_repo), using
-shared credentials.
+repositories, or run as workflows on the [source repositories](https://jupyter-releaser.readthedocs.io/en/latest/how_to_guides/convert_repo_from_repo), using shared credentials.

jupyter_releaser/actions/populate_release.py

@@ -29,14 +29,15 @@
 
 dry_run = os.environ.get("RH_DRY_RUN", "").lower() == "true"
 
-if not dry_run:
-    # Ensure the branch sha has not changed.
-    ensure_sha()
-
 if not os.environ.get("RH_RELEASE_URL"):
     raise RuntimeError("Cannot complete Draft Release, no draft GitHub release url found!")
 
 run_action("jupyter-releaser prep-git")
+
+if not dry_run:
+    # Ensure the branch sha has not changed.
+    ensure_sha()
+
 run_action("jupyter-releaser bump-version")
 run_action("jupyter-releaser extract-changelog")
 

jupyter_releaser/util.py

@@ -604,7 +604,7 @@ def ensure_sha():
     run(f"git fetch {remote_name} {branch}", echo=True)
     sha = run(f"git rev-parse {remote_name}/{branch}", echo=True)
     if sha != current_sha:
-        log(f"{branch} current sha {sha} is not equal to expected sha {current_sha}")
+        raise RuntimeError(f"{branch} current sha {sha} is not equal to expected sha {current_sha}")
 
 
 def get_gh_object(dry_run=False, **kwargs):