--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2291,7 +2291,8 @@ def revert(ui, repo, *pats, **opts):
"""
if not pats and not opts['all']:
- raise util.Abort(_('no files or directories specified'))
+ raise util.Abort(_('no files or directories specified; '
+ 'use --all to revert the whole repo'))
parent, p2 = repo.dirstate.parents()
if opts['rev']:
--- a/tests/test-revert.out
+++ b/tests/test-revert.out
@@ -55,7 +55,7 @@ executable
adding a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
% should fail - no arguments
-abort: no files or directories specified
+abort: no files or directories specified; use --all to revert the whole repo
% should succeed
reverting a
%% issue332