diff --git a/mercurial/templater.py b/mercurial/templater.py
--- a/mercurial/templater.py
+++ b/mercurial/templater.py
@@ -402,7 +402,7 @@ def stylelist():
         split = file.split(".")
         if split[0] == "map-cmdline":
             stylelist.append(split[1])
-    return ", ".join(stylelist)
+    return ", ".join(sorted(stylelist))
 
 class templater(object):
 
diff --git a/tests/test-command-template.t b/tests/test-command-template.t
--- a/tests/test-command-template.t
+++ b/tests/test-command-template.t
@@ -458,7 +458,8 @@ Error if style not readable:
 Error if no style:
 
   $ hg log --style notexist
-  abort: style not found: notexist
+  abort: style 'notexist' not found
+  (available styles: bisect, changelog, compact, default, phases, xml)
   [255]
 
 Error if style missing key:
diff --git a/tests/test-log.t b/tests/test-log.t
--- a/tests/test-log.t
+++ b/tests/test-log.t
@@ -88,7 +88,7 @@ log on directory
 
   $ hg log -f -l1 --style something
   abort: style 'something' not found
-  (available styles: changelog, bisect, default, xml, phases, compact)
+  (available styles: bisect, changelog, compact, default, phases, xml)
   [255]
 
 -f, phases style