Fetch history and tags in the canonical workflow (closes #110)

The checkout step of the canonical `.gitea/workflows/check.yml` now sets `fetch-depth: 0`, with a one-line comment saying why. The checkout action otherwise clones shallow with no tags, so `git describe --tags --always` gave a bare short commit id in CI where a local build of a tagged repository gives the tag. `REPO_POLICIES.md` and the existing repo checklist told each tagged repository to add it itself, which a byte-identical re-vendor would remove; they now say the canonical file sets it.

Unverified: the live check, which waits on the shared runner.

Model: opus-5-5

.gitea/workflows/check.yml

@@ -13,4 +13,6 @@ jobs:
               # script/cibuild needs no token, so none is left in .git/config.
               with:
                   persist-credentials: false
+                  # All history and tags, so git describe finds the version tag.
+                  fetch-depth: 0
             - run: script/cibuild

TODO.md

@@ -21,14 +21,13 @@ fmt-check, and commit.
 
 # Completed Steps
 
-- 2026-10-06: `REPO_POLICIES.md` and both checklists now say that a checkout
-  whose `.git` is a file, a linked worktree or a repository checked out as a
-  submodule, is the exception to a plain `docker build .` succeeding (issue
-  111): that file points to a git directory outside the build context, so the
-  build cannot read the version and the version check in the canonical
-  `Dockerfile` stops it. Such a build is given its version with
-  `--build-arg VERSION=...`, as `script/docker` and `script/cibuild` already do.
-  The check itself is unchanged.
+- 2026-10-06: The canonical `.gitea/workflows/check.yml` now sets
+  `fetch-depth: 0` on its checkout step (issue 110), so CI fetches the history
+  and tags that `git describe --tags --always` needs, and a tagged repository
+  stamps the same version in CI as in a local build. `REPO_POLICIES.md` and the
+  existing repo checklist now say the canonical file sets it, instead of asking
+  each repository to add it. Not yet tried on the shared runner, which is out of
+  disk space. Repositories pick this up on their next re-vendor.
 - 2026-10-06: The canonical `.gitea/workflows/check.yml` now has a `concurrency`
   block, so a new push cancels the older run on the same branch and no other,
   and its checkout step sets `persist-credentials: false`, so the job's token is

prompts/EXISTING_REPO_CHECKLIST.md

@@ -91,14 +91,10 @@ with your task.
       version still comes out empty, `dev` or `unknown`. A plain
       `docker build .` with no build arguments must succeed; a Dockerfile that
       refuses an empty build argument drops that refusal and keeps the argument.
-      A checkout whose `.git` is a file (a linked worktree, or a repository
-      checked out as a submodule) is the exception: that file points to a git
-      directory outside the build context, so the build cannot read the version
-      and a plain `docker build .` fails; pass the version with
-      `--build-arg VERSION=...`. `script/docker` and `script/cibuild` already
-      pass the version they compute on the host; it takes precedence. A
-      tag-derived version additionally needs `fetch-depth: 0` on the CI checkout
-      step, which clones shallow and fetches no tags by default.
+      `script/docker` and `script/cibuild` pass the version they compute on the
+      host; it takes precedence. The canonical `.gitea/workflows/check.yml` sets
+      `fetch-depth: 0` on its checkout step, which otherwise clones shallow and
+      fetches no tags, so a CI build finds the tag too.
 - [ ] Gitea Actions workflow in `.gitea/workflows/` runs `script/cibuild` on
       push, checks out with `persist-credentials: false`, and carries the
       `concurrency` block that lets a new push cancel only the same branch's

prompts/NEW_REPO_CHECKLIST.md

@@ -97,12 +97,6 @@ Template files can be fetched from:
       version still comes out empty, `dev` or `unknown`. A plain
       `docker build .` with no build arguments must succeed; a Dockerfile that
       refuses an empty build argument drops that refusal and keeps the argument.
-      A checkout whose `.git` is a file (a linked worktree, or a repository
-      checked out as a submodule) is the exception: that file points to a git
-      directory outside the build context, so the build cannot read the version
-      and a plain `docker build .` fails; pass the version with
-      `--build-arg VERSION=...`, as `script/docker` and `script/cibuild` already
-      do.
     - The Dockerfile carries a `lint` phase and a `test` phase, each invoking
       its tool directly rather than through `make` or `script/`, and the final
       stage carries a `COPY --from=` of a harmless file from each so the image

prompts/REPO_POLICIES.md

@@ -281,12 +281,6 @@ style conventions are in separate documents:
       `.git` and the version still comes out empty, `dev` or `unknown`. A plain
       `docker build .` with no build arguments must succeed; a Dockerfile that
       refuses an empty build argument drops that refusal and keeps the argument.
-      A checkout whose `.git` is a file (a linked worktree, or a repository
-      checked out as a submodule) is the exception: that file points to a git
-      directory outside the build context, so the build cannot read the version
-      and a plain `docker build .` fails; pass the version with
-      `--build-arg VERSION=...`, as `script/docker` and `script/cibuild` already
-      do.
 
 - Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
   runs `script/cibuild` on push, and checks out the repo as its only other step,
@@ -472,8 +466,8 @@ style conventions are in separate documents:
     there because `ARG` is stage-scoped; passing `VERSION` to a repo whose
     Dockerfile declares no such `ARG` is ignored and costs nothing, which is why
     the scripts stay byte-identical. One consequence for CI: the standard
-    checkout action clones shallow and fetches no tags, so a repo that embeds a
-    tag-derived version must set `fetch-depth: 0` on its checkout step.
+    checkout action clones shallow and fetches no tags, so the canonical
+    `.gitea/workflows/check.yml` sets `fetch-depth: 0` on its checkout step.
 
 - **Verify `.dockerignore` by enumerating the image, not by reading the
   patterns.** Plant files at the root _and_ at least two directories deep, build