diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8a5993f..9871b1c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -99,6 +99,30 @@ jobs:
           sudo install -m 0755 /tmp/cvc5-bin /usr/local/bin/cvc5
           cvc5 --version | head -1
 
+      # The semantics, solver and check suites read the OMG pilot corpora and the
+      # training corpus from examples/, as OpenSysML's own CI downloads them.
+      - name: Cache the OMG corpora
+        uses: actions/cache@v4
+        with:
+          path: |
+            opensysml/examples/sysml-v2-training
+            opensysml/examples/pilot-corpora
+          key: omg-corpora-${{ hashFiles('opensysml/scripts/download-training-examples.sh', 'opensysml/scripts/download-pilot-corpora.sh', 'opensysml/scripts/pilot-pin.sh') }}
+
+      - name: Download the OMG corpora
+        run: |
+          cd "$GITHUB_WORKSPACE/opensysml"
+          ./scripts/download-training-examples.sh
+          ./scripts/download-pilot-corpora.sh
+          for root in sysml-v2-training pilot-corpora/sysml-examples pilot-corpora/sysml-validation pilot-corpora/kerml-examples; do
+            count=$(find "examples/$root" -type f \( -name '*.sysml' -o -name '*.kerml' \) | wc -l)
+            echo "$root: $count model files"
+            if [ "$count" -eq 0 ]; then
+              echo "error: examples/$root is empty" >&2
+              exit 1
+            fi
+          done
+
       - name: Run OpenSysML against these libraries
         env:
           EXTENSIONS_DIR: ${{ github.workspace }}/extensions
@@ -110,4 +134,5 @@ jobs:
           fi
           scripts/sync-extension-libraries.sh --source "$EXTENSIONS_DIR"
           make stdlib-snapshot-check || make stdlib-snapshot
-          go test ./internal/workspace/libs/... ./internal/exec/... ./internal/ir/... ./internal/doc/... ./internal/semantic/... ./internal/check/... ./internal/translate/... ./tests/hygiene/...
+          # internal/exec/runtime and internal/exec/smt outlast go test's default 10m on these runners.
+          go test -timeout 60m ./internal/workspace/libs/... ./internal/exec/... ./internal/ir/... ./internal/doc/... ./internal/semantic/... ./internal/check/... ./internal/translate/... ./tests/hygiene/...
diff --git a/README.md b/README.md
index 479b66b..ca7d699 100644
--- a/README.md
+++ b/README.md
@@ -67,7 +67,11 @@ Every tool also needs the OMG standard library (`sysml.library`).
 - **OpenSysML** — bundled: it vendors a pinned copy at
   `internal/workspace/libs/stdlib/OpenSysML Libraries/`, pinned by
   `scripts/extension-libraries-pin.sh` and refreshed by
-  `scripts/sync-extension-libraries.sh`. Edits land here first.
+  `scripts/sync-extension-libraries.sh`. Edits land here first. A newer
+  revision than the bundled one is read as a project interchange archive:
+  name the release `.kpar` beside the model
+  (`sysml -validate model.sysml opensysml-extension-libraries.kpar`) or put it
+  under a `-library-root` directory.
 
 ## Versioning