Add a nightly gha to track the dependency incompatibility

Author: iddm

.github/workflows/nightly-deps.yml

@@ -0,0 +1,106 @@
+name: Nightly Dependency Update
+
+# Rebuilds the crate against the latest compatible versions of its dependencies
+# (`cargo update`) every night. Because several dependencies are intentionally
+# unbounded (e.g. `windows = ">=0.61"`, `libc = ">=0.2.123"`), a newly published
+# version may break compilation; this job surfaces that early by opening an issue.
+
+on:
+  schedule:
+    # One hour after the regular nightly build so they don't run at once.
+    - cron: '0 3 * * *'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  issues: write
+
+jobs:
+  test:
+    name: Test (updated deps)
+    runs-on: ${{ matrix.os || 'ubuntu-latest' }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        name:
+          - stable
+          - beta
+          - nightly
+          - macOS
+          - Windows
+
+        include:
+          - name: beta
+            toolchain: beta
+          - name: nightly
+            toolchain: nightly
+          - name: macOS
+            os: macOS-latest
+          - name: Windows
+            os: windows-latest
+
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Install toolchain
+        id: tc
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.toolchain || 'stable' }}
+          profile: minimal
+          override: true
+
+      # No build cache here on purpose: freshness is the whole point, a cached
+      # target/ keyed on Cargo.toml could otherwise mask a newly published version.
+      - name: Update dependencies to latest
+        run: cargo update --verbose
+
+      - name: Build all features
+        if: matrix.features == ''
+        run: cargo build --all-features
+
+      - name: Test all features (other)
+        if: matrix.features == '' && runner.os != 'Linux'
+        run: cargo test --all-features -- --skip set_deadline_policy
+
+      - name: Test all features (Linux)
+        if: matrix.features == '' && runner.os == 'Linux'
+        run: sudo -E /home/runner/.cargo/bin/cargo test --all-features
+
+  report:
+    name: Report failure
+    needs: test
+    if: failure()
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Open or update tracking issue
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+        run: |
+          set -euo pipefail
+          label="nightly-deps"
+
+          # Make sure the label exists (no-op if it already does).
+          gh label create "$label" --color B60205 \
+            --description "Nightly dependency-update build failures" || true
+
+          body="The nightly job that runs \`cargo update\` and rebuilds against the latest compatible dependency versions has **failed**.
+
+          This usually means a newly published version of an unbounded dependency (e.g. \`windows = \">=0.61\"\`, \`libc = \">=0.2.123\"\`) no longer compiles or passes the tests. Consider pinning an upper bound until it is resolved.
+
+          Failed run: $RUN_URL"
+
+          existing=$(gh issue list --state open --label "$label" --json number --jq '.[0].number // empty')
+
+          if [ -n "$existing" ]; then
+            gh issue comment "$existing" --body "Nightly dependency update failed again: $RUN_URL"
+          else
+            gh issue create \
+              --title "Nightly dependency update broke the build" \
+              --label "$label" \
+              --body "$body"
+          fi