ci: run daily and notify if failures (#520)

Author: v1v

.buildkite/pipeline.yml

@@ -155,3 +155,8 @@ steps:
           provider: "gcp"
           image: "${IMAGE_UBUNTU_X86_64}"
           instanceType: "${INSTANCE_TYPE_X86_64}"
+
+# TODO: look for the right slack channel. Robots team don't own this project.
+notify:
+  - slack: "#observablt-bots"
+    if: build.state == "failed"

catalog-info.yaml

@@ -59,6 +59,11 @@ spec:
           access_level: BUILD_AND_READ
         everyone:
           access_level: READ_ONLY
+      schedules:
+        Daily:
+          branch: main
+          cronline: "0 12 * * * America/New_York"
+          message: "Builds once per day"
 
 ---
 # yaml-language-server: $schema=https://gist.githubusercontent.com/elasticmachine/988b80dae436cafea07d9a4a460a011d/raw/e57ee3bed7a6f73077a3f55a38e76e40ec87a7cf/rre.schema.json