Separate linkcheck job from doc building

.github/workflows/ci.yml

@@ -73,10 +73,21 @@ jobs:
           pip install tox-uv
           tox -e lint-${{ matrix.py-version.tox }}
 
+  lychee:
+    name: "Link Check"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+      - uses: lycheeverse/lychee-action@e7477775783ea5526144ba13e8db5eec57747ce8 # v2.9.0
+        with:
+          args: -vv --root-dir ${{ github.workspace }} --config lychee.toml baybe docs examples README.md CONTRIBUTING.md CHANGELOG.md
+
   build-docs:
     name: "Build Docs"
     runs-on: ubuntu-latest
-    needs: [lint]
+    needs: [lint, lychee]
     permissions:
       contents: read
       pages: write     # Required to deploy to GitHub Pages

docs/scripts/check_links.py

@@ -1,16 +1,16 @@
-"""Utility for checking the links of the documentation."""
+"""Utility for checking the cross-references of the documentation."""
 
 from subprocess import check_call
 
 
 def check_links() -> None:
-    """Check whether the links of the documentation are valid."""
-    link_call = [
-        "sphinx-build",
-        "-b",
-        "linkcheck",
-        "docs",
-        "docs/build",
-    ]
-
-    check_call(link_call)
+    """Check that documentation cross-references resolve (external links: lychee)."""
+    check_call(
+        [
+            "sphinx-build",
+            "-b",
+            "dummy",
+            "docs",
+            "docs/build",
+        ]
+    )

lychee.toml

@@ -0,0 +1,7 @@
+# External link check. Keep `exclude` in sync with `linkcheck_ignore` in docs/conf.py.
+scheme = ["https", "http"]
+exclude = [
+    "https://github\\.com/b-shields/edbo/blob.*",
+    "https://doi\\.org/10\\.26434/chemrxiv\\.10001986/v2",
+    "https://doi\\.org/10\\.1039/D5DD00050E",
+]