chore: Fix releaser to support checking the current latest release.

This addresses the situation where release candidates go wrong and we
don't actually release them.

.github/workflows/build-test-deploy.yaml

@@ -63,7 +63,6 @@ jobs:
             git checkout master
             git checkout release-head
           fi
-          echo "prev-version=$(git describe --tags --abbrev=0 --match 'v*')" >>$GITHUB_OUTPUT
       - name: Verify release
         if: steps.create-identity.outputs.next-version != ''
         env:
@@ -84,7 +83,7 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: tools/create_release.py
-          --version "${{ steps.create-identity.outputs.prev-version }}"
+          --version latest
           --upstream origin
           --dryrun
 

tools/create_release.py

@@ -88,7 +88,8 @@ def parse_args() -> Config:
     )
     parser.add_argument(
         "--version",
-        help="Version to release. Default: next milestone",
+        help="Version to release. The special value 'latest' means the "
+        "current latest release on GitHub. Default: next milestone",
         default="",
     )
     parser.add_argument(
@@ -116,6 +117,11 @@ def stage_version(config: Config) -> str:
         s.ok(git.branch_sha(f"{config.upstream}/{config.main_branch}")[:7])
     with stage.Stage("Version", "Determine the upcoming version") as s:
         if config.version:
+            if config.version == "latest":
+                version = github.latest_release()
+                s.ok(f"Using latest release {version}")
+                return version
+
             require(
                 re.match(git.VERSION_REGEX, config.version) is not None,
                 f"Invalid version: {config.version} "
@@ -285,6 +291,9 @@ def stage_pull_request(
 
 
 def stage_restyled(config: Config, version: str, parent: stage.Stage) -> None:
+    if config.verify:
+        # Can't do this on CI.
+        return
     with stage.Stage("Restyled", "Applying restyled fixes",
                      parent=parent) as s:
         subprocess.run(["hub-restyled"], check=True)  # nosec

tools/lib/github.py

@@ -229,6 +229,14 @@ def open_milestone_issues(milestone: int) -> list[Issue]:
     ]
 
 
+def latest_release() -> str:
+    """Get the name of the current release in the repository.
+
+    Includes prereleases.
+    """
+    return api(f"/repos/{repository()}/releases/latest")["tag_name"]
+
+
 def prereleases(version: str) -> list[str]:
     """Get the names of all prereleases for a given version in the repository."""
     return [