diff --git a/.github/scripts/generate-build-matrix.py b/.github/scripts/generate-build-matrix.py
index 18079b28..0bb23910 100755
--- a/.github/scripts/generate-build-matrix.py
+++ b/.github/scripts/generate-build-matrix.py
@@ -10,6 +10,7 @@
 
 import copy
 import json
+import sys
 
 BASE_MATRIX = [
     {
@@ -72,6 +73,7 @@ def main():
                 config["linkage"] = linkage
                 matrix.append(config)
 
+    print(json.dumps({"include": matrix}), file=sys.stderr)
     print(json.dumps({"include": matrix}))