Timers, and a file abstraction that works without an operating system

.github/workflows/publish.yml

@@ -0,0 +1,49 @@
+name: Publish
+
+# House scheme: a version bump on the default branch is the release. No tags,
+# no manual step. Publishing is irreversible, so the trigger has to be
+# something you cannot do by accident, and editing the version field is that.
+#
+# This crate's default branch is `master`, unlike ps-st3's `main`. Match the
+# repository rather than copying the sibling, or the workflow silently never
+# runs and the release looks like it worked.
+on:
+  push:
+    branches: [master]
+    paths: ['Cargo.toml']
+
+jobs:
+  publish:
+    runs-on: ubicloud-standard-2
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 2
+      - uses: dtolnay/rust-toolchain@stable
+
+      - id: version
+        run: |
+          new=$(sed -nE '0,/^version = "(.*)"/s//\1/p' Cargo.toml)
+          old=$(git show HEAD^:Cargo.toml | sed -nE '0,/^version = "(.*)"/s//\1/p')
+          if [ "$new" = "$old" ]; then
+            echo "version unchanged at $new, nothing to publish"
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+          else
+            echo "version $old -> $new"
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          fi
+
+      # The gate runs on this commit too, but a release must not depend on job
+      # ordering, so it is re-run here rather than assumed.
+      - if: steps.version.outputs.changed == 'true'
+        run: cargo test --release
+
+      # `no_std` is the reason this crate exists, so a release that only builds
+      # with an operating system underneath it is not a release.
+      - if: steps.version.outputs.changed == 'true'
+        run: cargo check --no-default-features
+
+      - if: steps.version.outputs.changed == 'true'
+        run: cargo publish --token "$CARGO_REGISTRY_TOKEN"
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}

.gitignore

@@ -1,2 +1,3 @@
 /target
+/target-*
 /Cargo.lock