Fix doc build on tag (#1577)

Author: mattip

.circleci/config.yml

@@ -644,6 +644,12 @@ workflows:
           - download_third_parties_nix
       - binary_linux_wheel:
           cuda_version: cpu
+          filters:
+            branches:
+              only:
+              - /.*/
+            tags:
+              only: /v[0-9]+(\.[0-9]+)*-rc[0-9]+/
           name: binary_linux_wheel_py3.8_cpu
           python_version: '3.8'
           requires:
@@ -771,6 +777,12 @@ workflows:
           name: binary_windows_conda_py3.9_cpu
           python_version: '3.9'
       - build_docs:
+          filters:
+            branches:
+              only:
+              - /.*/
+            tags:
+              only: /v[0-9]+(\.[0-9]+)*-rc[0-9]+/
           name: build_docs
           python_version: '3.8'
           requires:

.circleci/regenerate.py

@@ -36,14 +36,20 @@ def build_workflows(prefix='', upload=False, filter_branch=None, indentation=6):
         for os_type in ["linux", "macos", "windows"]:
             for python_version in PYTHON_VERSIONS:
                 for cu_version in CU_VERSIONS_DICT[os_type]:
+                    fb = filter_branch
                     if cu_version.startswith("rocm") and btype=="conda":
-                        pass
-                    else:
-                        w += build_workflow_pair(btype, os_type, python_version, cu_version, filter_branch, prefix, upload)
+                        continue
+                    if not fb and (os_type == 'linux' and
+                                   btype == 'wheel' and
+                                   python_version == '3.8' and
+                                   cu_version == 'cpu'):
+                        # the fields must match the build_docs "requires" dependency
+                        fb = '/.*/'
+                    w += build_workflow_pair(btype, os_type, python_version, cu_version, fb, prefix, upload)
 
     if not filter_branch:
         # Build on every pull request, but upload only on nightly and tags
-        w += build_doc_job(None)
+        w += build_doc_job('/.*/')
         w += upload_doc_job('nightly')
         w += docstring_parameters_sync_job(None)