builder: Fix some places that assume there is always a remote cache

1 files changed, 11 insertions, 7 deletions

diff --git a/morphlib/builder.py b/morphlib/builder.py
index 4b659984..00955abe 100644
--- a/morphlib/builder.py
+++ b/morphlib/builder.py
@@ -476,11 +476,14 @@ class StratumBuilder(BuilderBase):
             constituent_sources = {d.source for d in constituents}
 
             # the only reason the StratumBuilder has to download chunks is to
-            # check for overlap now that strata are lists of chunks
+            # check for overlap now that strata are lists of chunks. If there
+            # is no remote artifact cache, we assume they're all cached
+            # locally.
             with self.build_watch('check-chunks'):
-                self.remote_artifact_cache.get_artifacts_for_sources(
-                    constituent_sources, self.local_artifact_cache,
-                    status_cb=self.app.status)
+                if self.remote_artifact_cache:
+                    self.remote_artifact_cache.get_artifacts_for_sources(
+                        constituent_sources, self.local_artifact_cache,
+                        status_cb=self.app.status)
 
             with self.build_watch('create-chunk-list'):
                 lac = self.local_artifact_cache
@@ -572,9 +575,10 @@ class SystemBuilder(BuilderBase):  # pragma: no cover
                 self.source.dependencies)
 
             # download the stratum and chunk artifacts if necessary
-            self.remote_artifact_cache.get_artifacts_for_sources(
-                dep_sources, self.local_artifact_cache,
-                status_cb=self.app.status)
+            if self.remote_artifact_cache:
+                self.remote_artifact_cache.get_artifacts_for_sources(
+                    dep_sources, self.local_artifact_cache,
+                    status_cb=self.app.status)
 
             # unpack it from the local artifact cache
             for stratum_artifact in self.source.dependencies: