error out when packages cannot be loaded

related to #10

PiperOrigin-RevId: 716161251
Change-Id: If93b601e2dc7a491839d076cdea59f5a18993612

internal/o2o/loader/loaderblaze.go

diff --git a/internal/o2o/loader/loaderblaze.go b/internal/o2o/loader/loaderblaze.go
index 6c173ef..2a7a35c 100644
--- a/internal/o2o/loader/loaderblaze.go
+++ b/internal/o2o/loader/loaderblaze.go
@@ -73,6 +73,10 @@
 			failBatch(targets, res, fmt.Errorf("BUG: Load() returned package %s, which was not requested", pkg.ID))
 			return
 		}
+		if len(pkg.Errors) > 0 {
+			failBatch(targets, res, fmt.Errorf("Loading package failed:\n%s", pkg.Errors))
+			return
+		}
 	}
 
 LoadedPackage: