Register source_obj as dependency for all artifacts (that have one)

lektor/build_programs.py

@@ -5,7 +5,6 @@
 from lektor.assets import Directory
 from lektor.assets import File
 from lektor.constants import PRIMARY_ALT
-from lektor.context import get_ctx
 from lektor.db import Attachment
 from lektor.db import Page
 from lektor.exception import LektorException
@@ -177,9 +176,8 @@ def produce_artifacts(self):
             )
 
     def build_artifact(self, artifact):
-        # Record dependecies on all our sources and datamodel
-        get_ctx().track_source_dependency(self.source)
-
+        # FIXME: This check should probably be moved into Artifact so that it
+        # is applied for all artifacts, not just those built from Pages.
         try:
             self.source.url_path.encode("ascii")
         except UnicodeError as error:

lektor/builder.py

@@ -663,7 +663,12 @@ def __repr__(self):
 
 
 class Artifact:
-    """This class represents a build artifact."""
+    """This class represents a build artifact.
+
+    :param sources: The _primary sources_ for the artifact.
+        If none of the primary sources for an artifact exist, the artifact
+        will be considered obsolete and will be deleted at the next pruning.
+    """
 
     def __init__(
         self,
@@ -933,8 +938,11 @@ def update(self):
         """
         ctx = self.begin_update()
         try:
+            if self.source_obj:
+                # Record dependencies on all sources and datamodel
+                ctx.track_source_dependency(self.source_obj)
             yield ctx
-        except:  # pylint: disable=bare-except  # noqa
+        except BaseException:
             exc_info = sys.exc_info()
             self.finish_update(ctx, exc_info)
         else: