release: prepare 0.5.0 candidate and migration guidance

CHANGELOG.md

@@ -11,6 +11,8 @@ and versions are tracked in the repo-root `VERSION` file.
 
 - Continue compatibility hardening and adoption work for the next release.
 
+## [0.5.0] - 2026-10-03
+
 ### Added
 
 - Publish versioned, comparative CLI benchmark reports with lifecycle and
@@ -391,7 +393,8 @@ the API stability policy and migration guide before upgrading from `0.3.x`.
 - Pinned the build backend to metadata compatible with the bundled publication
   action and made license-file validation portable across setuptools versions.
 
-[Unreleased]: https://github.com/basefoundry/base-cli/compare/v0.4.3...HEAD
+[Unreleased]: https://github.com/basefoundry/base-cli/compare/v0.5.0...HEAD
+[0.5.0]: https://github.com/basefoundry/base-cli/compare/v0.4.3...v0.5.0
 [0.4.3]: https://github.com/basefoundry/base-cli/compare/v0.4.2...v0.4.3
 [0.4.2]: https://github.com/basefoundry/base-cli/compare/v0.4.1...v0.4.2
 [0.4.1]: https://github.com/basefoundry/base-cli/compare/v0.4.0...v0.4.1

README.md

@@ -7,7 +7,9 @@
 
 | Version | License | Install | Release notes |
 | --- | --- | --- | --- |
-| `0.4.3` | [Apache-2.0](LICENSE) | `python -m pip install base-cli` | [v0.4.3](https://github.com/basefoundry/base-cli/releases/tag/v0.4.3) |
+| `0.5.0` | [Apache-2.0](LICENSE) | `python -m pip install base-cli` | [v0.5.0](https://github.com/basefoundry/base-cli/releases/tag/v0.5.0) |
+
+Source release candidate: 0.5.0. Publication is pending the [release checklist](docs/release-0.5.0-checklist.md); PyPI remains the authority for available versions.
 
 `base-cli` is the production lifecycle layer for Click and Typer Python CLIs.
 It standardizes context, logging, configuration, cleanup, and machine-readable

VERSION

@@ -1 +1 @@
-0.4.3
+0.5.0

docs/migration-0.5.md

@@ -0,0 +1,28 @@
+# Migrating from 0.4.x to 0.5.0
+
+0.5.0 is a pre-1.0 minor release. It retains the Click/Typer lifecycle APIs while
+strengthening configuration, output, logging, retention, and release contracts.
+The published 0.4.3 tag and distributions remain immutable.
+
+- Convenience-profile project configuration now validates POSIX ownership and
+  permissions, refuses symlink/reparse paths, and stops discovery at `.git`, a
+  filesystem boundary, or the configured ancestor limit. Repair permissions or
+  make the shared-workspace opt-out explicit; see [local configuration](local-config.md).
+- YAML inputs are bounded before alias construction. Split unusually large
+  configuration files and remove recursive or excessive alias graphs.
+- JSON mode captures descriptor and inherited child stdout. Wait for children
+  and flush native stdio before returning. Output over 8 MiB produces an error;
+  use NDJSON for larger streams. See [JSON contracts](json-contracts.md).
+- Consumer logging handlers and configured levels survive CLI cleanup. A host
+  level may filter persistent DEBUG messages; configure the host logger at DEBUG
+  when those are required. See [integrations](integrations.md).
+- Native Windows enforces bundle retention through pinned directory handles;
+  contended maintenance passes skip without blocking command execution.
+- Repeated source paths and human log timestamps are cached; log-sidecar I/O
+  errors use logging's error path without aborting commands.
+- Click 8.5 is supported within the declared Click window. Typer consumers must
+  use the documented compatible Click/Typer pairs.
+
+Review the dated [changelog](https://github.com/basefoundry/base-cli/blob/main/CHANGELOG.md) and the [platform boundary](platform-support.md)
+when upgrading. Test the installed wheel in a clean environment, including your
+JSON consumers, config permissions, and host logging integration.

docs/release-0.5.0-checklist.md

@@ -0,0 +1,26 @@
+# 0.5.0 release candidate checklist
+
+This is release preparation. A dated changelog section does not mean the version
+has been tagged or published. The proposed date must be refreshed if publication
+happens on another day. Issue #307 remains open until publication evidence exists.
+
+1. Merge the reviewed 0.5.0 issue train and all remaining 0.5.0 PRs. Refresh the
+   release PR against their final integrated commit and include their changelog
+   entries in 0.5.0 before approval.
+2. Obtain independent approval and passing required checks on the exact release
+   head. Keep the repository and environment approval rules in place.
+3. Validate the 0.4.x migration boundary in [migration guidance](migration-0.5.md),
+   then run the full local gate and hosted platform, dependency, consumer,
+   benchmark, package, and provenance checks.
+4. Rehearse the reviewed artifact through the protected TestPyPI environment.
+   Install exactly `base-cli==0.5.0` from a new environment and run lifecycle/JSON
+   smoke checks; retain the artifact digest and workflow URL.
+5. After the release PR is merged, create annotated `v0.5.0` on the independently
+   approved protected-main commit. Never alter `v0.4.3` or its distributions.
+6. Approve the protected production environment. Publish the exact reviewed
+   wheel/sdist, then verify matching SHA256SUMS, SPDX SBOM, provenance and SBOM
+   attestations, RELEASE-BOM-ROW, tag target, and GitHub release assets.
+7. Verify a clean installation of exactly `base-cli==0.5.0` from PyPI. Record the
+   immutable release URL and evidence on #307, then close it.
+
+The operational commands and recovery rules remain in [Releasing](releasing.md).

docs/releasing.md

@@ -204,3 +204,11 @@ rerun the workflow before creating a tag. If TestPyPI succeeds but a production
 publish fails, inspect the workflow logs and rerun the same approved tag only
 after confirming that neither artifact nor metadata needs correction. A version
 that was published successfully must be incremented for the next release.
+
+## 0.5.0 preparation
+
+Use the [0.5.0 checklist](release-0.5.0-checklist.md) and
+[0.4.x migration notes](migration-0.5.md). The changelog validator permits the
+newest section matching `VERSION` to precede its tag while preparing a release
+PR; all earlier published sections remain checked against their tags. Once the
+current tag exists, its section is immutable too.

mkdocs.yml

@@ -45,6 +45,7 @@ nav:
       - Dependency support: dependency-support.md
       - Optional output dependencies: optional-output-dependencies.md
       - Migration guide: migrations.md
+      - Migrating to 0.5.0: migration-0.5.md
       - Click migration: migration-click.md
       - Typer migration: migration-typer.md
       - Cement migration: migration-cement.md
@@ -66,3 +67,4 @@ nav:
       - Runtime threat model: security-threat-model.md
       - Security release review: security-review.md
       - Releasing base-cli: releasing.md
+      - 0.5.0 release checklist: release-0.5.0-checklist.md

scripts/validate_changelog.py

@@ -129,6 +129,8 @@ def _validate_published_sections(
     """Ensure every released section remains identical to its version tag."""
 
     errors: list[str] = []
+    version_file = path.parent / "VERSION"
+    candidate = version_file.read_text(encoding="utf-8").strip() if version_file.is_file() else None
     for version in versions:
         if version == "Unreleased":
             continue
@@ -141,6 +143,18 @@ def _validate_published_sections(
                 text=True,
             )
         except (OSError, subprocess.CalledProcessError) as exc:
+            # A release PR necessarily precedes its protected-main tag. Only
+            # the newest section matching VERSION may be an untagged candidate;
+            # every earlier release remains bound to its immutable tag.
+            if version == candidate and len(versions) > 1 and version == versions[1]:
+                exists = subprocess.run(
+                    ["git", "-C", str(path.parent), "rev-parse", "--verify", f"refs/tags/{tag}"],
+                    capture_output=True,
+                    text=True,
+                    check=False,
+                )
+                if exists.returncode == 1 or exists.returncode == 128:
+                    continue
             detail = getattr(exc, "stderr", None) or str(exc)
             errors.append(
                 f"cannot verify [{version}] against tag {tag}: {detail.strip()}; "

scripts/validate_docs.py

@@ -33,12 +33,14 @@
         "migration-click.md",
         "migration-typer.md",
         "migrations.md",
+        "migration-0.5.md",
         "output-contracts.md",
         "optional-output-dependencies.md",
         "performance.md",
         "testing.md",
         "platform-support.md",
         "releasing.md",
+        "release-0.5.0-checklist.md",
         "security-review.md",
         "security-threat-model.md",
         "schemas.md",

tests/test_validate_changelog.py

@@ -78,6 +78,19 @@ def test_rejects_edits_to_a_published_section(self) -> None:
                 errors = validate_changelog.validate_changelog(path, verify_tags=True)
         self.assertIn("published changelog section [1.0.0] differs from tag v1.0.0", errors)
 
+    def test_current_untagged_release_candidate_can_be_prepared(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            path = Path(tmpdir) / "CHANGELOG.md"
+            path.write_text(VALID_CHANGELOG, encoding="utf-8")
+            (path.parent / "VERSION").write_text("1.0.0\n")
+            missing = subprocess.CalledProcessError(128, "git", stderr="missing tag")
+            with mock.patch(
+                "scripts.validate_changelog.subprocess.run",
+                side_effect=[missing, subprocess.CompletedProcess("git", 128)],
+            ):
+                errors = validate_changelog.validate_changelog(path, verify_tags=True)
+            self.assertEqual(errors, [])
+
     def test_reports_unavailable_release_tags(self) -> None:
         with tempfile.TemporaryDirectory() as directory:
             path = Path(directory) / "CHANGELOG.md"