allow help(sh)

CHANGELOG.md

@@ -8,6 +8,7 @@
 *   more efficiently closing inherited fds [#406](https://github.com/amoffat/sh/issues/406)
 *   bugfix where passing invalid dictionary to `_env` will cause a mysterious child 255 exit code. [#497](https://github.com/amoffat/sh/pull/497)
 *   bugfix where `_in` using 0 or `sys.stdin` wasn't behaving like a TTY, if it was in fact a TTY. [#514](https://github.com/amoffat/sh/issues/514)
+*   bugfix where `help(sh)` raised an exception [#455](https://github.com/amoffat/sh/issues/455)
 
 ## 1.12.14 - 6/6/17
 *   bugfix for poor sleep performance [#378](https://github.com/amoffat/sh/issues/378)

sh.py

@@ -50,6 +50,7 @@
 from functools import partial
 import inspect
 import tempfile
+import warnings
 import stat
 import glob as glob_module
 import ast
@@ -3229,9 +3230,8 @@ def __getitem__(self, k):
 
         # somebody tried to be funny and do "from sh import *"
         if k == "__all__":
-            raise RuntimeError("Cannot import * from sh. \
-Please import sh or import programs individually.")
-
+            warnings.warn("Cannot import * from sh. Please import sh or import programs individually.")
+            return []
 
         # check if we're naming a dynamically generated ReturnCode exception
         exc = get_exc_from_name(k)