fix(build): raise clear error if mkdocs.yml config file is missing

readthedocs/doc_builder/backends/mkdocs.py

@@ -5,15 +5,16 @@
 """
 
 import os
-
 import structlog
-import yaml
 from django.conf import settings
 
 from readthedocs.core.utils.filesystem import safe_open
 from readthedocs.doc_builder.base import BaseBuilder
+from readthedocs.doc_builder.exceptions import BuildUserError
 from readthedocs.projects.constants import MKDOCS
 from readthedocs.projects.constants import MKDOCS_HTML
+from readthedocs.doc_builder.exceptions import ProjectConfigurationError
+
 
 
 log = structlog.get_logger(__name__)
@@ -99,6 +100,10 @@ def build(self):
             "--config-file",
             os.path.relpath(self.yaml_file, self.project_path),
         ]
+
+        if not os.path.exists(self.yaml_file):
+            raise ProjectConfigurationError(ProjectConfigurationError.NOT_FOUND)
+
         if self.config.mkdocs.fail_on_warning:
             build_command.append("--strict")
         cmd_ret = self.run(