Include underlying httpcore exception tracebacks (#1199)

diff --git a/httpx/_exceptions.py b/httpx/_exceptions.py
index 9a46d7d24a7054915acbad4e06824cb188284894..4d6837778a1f02fbdceea0630cf66e13f91bee91 100644 (file)
--- a/httpx/_exceptions.py
+++ b/httpx/_exceptions.py
@@ -356,7 +356,7 @@ def map_exceptions(
             raise
 
         message = str(exc)
-        raise mapped_exc(message, **kwargs) from None  # type: ignore
+        raise mapped_exc(message, **kwargs) from exc  # type: ignore
 
 
 HTTPCORE_EXC_MAP = {