Fix WSGIAppError rewrapping

gabbi/case.py

@@ -29,6 +29,8 @@
 from unittest import result as unitresult
 import urllib.parse as urlparse
 
+import wsgi_intercept
+
 from gabbi import __version__
 from gabbi import exception
 from gabbi.handlers import base
@@ -500,14 +502,19 @@ def _run_request(
         if 'user-agent' not in (key.lower() for key in headers):
             headers['user-agent'] = "gabbi/%s (Python urllib3)" % __version__
 
-        response, content = self.http.request(
-            url,
-            method=method,
-            headers=headers,
-            body=body,
-            redirect=redirect,
-            timeout=timeout,
-        )
+        try:
+            response, content = self.http.request(
+                url,
+                method=method,
+                headers=headers,
+                body=body,
+                redirect=redirect,
+                timeout=timeout,
+            )
+        except wsgi_intercept.WSGIAppError as exc:
+            # Extract and re-raise the wrapped exception.
+            raise exc.exception_type(exc.exception_value).with_traceback(
+                   exc.traceback) from None
 
         # Set headers and location attributes for follow on requests
         self.response = response