diff -r 2a42ca2679e2 -r 1cb54e6193a6 mercurial/httppeer.py
--- a/mercurial/httppeer.py	Sat Apr 14 02:06:03 2018 +0530
+++ b/mercurial/httppeer.py	Fri Apr 13 18:17:45 2018 -0400
@@ -754,7 +754,8 @@
                         try:
                             result.append(decoder.decode())
                         except Exception:
-                            f.set_exception_info(*sys.exc_info()[1:])
+                            pycompat.future_set_exception_info(
+                                f, sys.exc_info()[1:])
                             continue
                 else:
                     result.append(meta['data'])