Fix busted nightly_job_basis and add warning

tf_oss_dashboard/dashboard.py

@@ -139,8 +139,11 @@ for record in all_records:
 # included in the nightly jobs if it was committed before a nightly job's
 # commit. This way we can quickly tell when a commit was first tested in a TF
 # Nightly test.
-if YAML_CONFIG["nightly_job_basis"]:
-  nightlies = job_names_to_records[YAML_CONFIG["nightly_job_basis"]]
+if "nightly_job_basis" in YAML_CONFIG:
+  basis = YAML_CONFIG["nightly_job_basis"]
+  if basis not in job_names_to_records:
+    exit(f"nightly_job_basis has been set to '{basis}', but those results are missing. Is the configuration correct?")
+  nightlies = job_names_to_records[basis]
   for name, records in job_names_to_records.items():
     for record in records:
       for nightly in nightlies:

tf_oss_dashboard/tensorflow.yaml

@@ -110,7 +110,7 @@ default_category: Everything Else
 # Use this to determine which commits are the Nightly ones when comparing.
 # Set it to false to disable all "Nightly" features (i.e. the "in nightly..."
 # or "this is nightly" badge in a commit)
-nightly_job_basis: Nightly - Code Check - Linux
+nightly_job_basis: Nightly - Code Check (Full)
 # Configures how large a job card can grow (that is, how many dots will appear
 # on it). A date tag is size 3, and a status dot is size 1.
 maximum_card_size: 100