Refs #3646 -- include stdout in the output when spawning a process fails in the release script (#3671)

diff --git a/release.py b/release.py
index e7a0080..0016b65 100644
--- a/release.py
+++ b/release.py
@@ -25,7 +25,12 @@
 
 def run(*args, **kwargs):
     kwargs.setdefault("stderr", subprocess.STDOUT)
-    subprocess.check_output(list(args), **kwargs)
+    try:
+        subprocess.check_output(list(args), **kwargs)
+    except subprocess.CalledProcessError as e:
+        # Reraise this with a different type so that str(e) is somethign with
+        # stdout in it.
+        raise Exception(e.cmd, e.returncode, e.output)
 
 
 def wait_for_build_completed(session):