Improve trychange.py documentation. No logic change

trychange.py

Index: trychange.py
diff --git a/trychange.py b/trychange.py
index ead63c338d32956a5a90613179a4deed92de8e8f..4dc3beb831bbcd9b196c3c1962ae3186dfa5522c 100755
--- a/trychange.py
+++ b/trychange.py
@@ -535,10 +535,14 @@ def TryChange(argv,
   parser.add_option_group(group)
 
   group = optparse.OptionGroup(parser, "Try job options")
-  group.add_option("-b", "--bot", action="append",
-                    help="Only use specifics build slaves, ex: "
-                         "'--bot win,layout_mac'; see the try "
-                         "server waterfall for the slave's name")
+  group.add_option(
+      "-b", "--bot", action="append",
+      help=("IMPORTANT: specify ONE builder per --bot flag. Use it multiple "
+            "times to specify multiple builders. ex: "
+            "'-bwin_rel:ui_tests,webkit_unit_tests -bwin_layout'. See "
+            "the try server waterfall for the builders name and the tests "
+            "available. Can also be used to specify gtest_filter, e.g. "
+            "-bwin_rel:base_unittests:ValuesTest.*Value"))

[Nico, 2012/10/15 23:24:09]

Why this change? The lhs doc permitted "win,layout_mac", and that still seems to
work in practice. It's much more convenient to type too.

Can I revert this documentation change, and support ',' in `git cl try` too?

[Peter Mayo, 2012/10/15 23:41:41]

This leads to paths that are too hard to communicate unambiguously.

eg: 
win:ui_tests,layout_mac 
win,layout_mac:unit

in the end, picking one interpretation of these is going to end up with
situations that people aren't running the tests they think they are.

With one builder per bot: the interpretation & scope of test-limiting options is
 - clearer to people
 - easier to parse in python
 - more easily transformed by defaults
 - compared to requirements in the CQ

In other words, FWIW: -1.

   group.add_option("-B", "--print_bots", action="store_true",
                     help="Print bots we would use (e.g. from PRESUBMIT.py)"
                          " and exit.  Do not send patch.  Like --dry_run"
@@ -558,13 +562,11 @@ def TryChange(argv,
                    help="Override which project to use. Projects are defined "
                         "server-side to define what default bot set to use")
 
-  group.add_option("-t", "--testfilter", action="append", default=[],
-                   help="Add a gtest_filter to a test. Use multiple times to "
-                        "specify filters for different tests. (i.e. "
-                        "--testfilter base_unittests:ThreadTest.* "
-                        "--testfilter ui_tests) If you specify any testfilters "
-                        "the test results will not be reported in rietveld and "
-                        "only tests with filters will run.")
+  group.add_option(
+      "-t", "--testfilter", action="append", default=[],
+      help=("Apply a testfilter to all the selected builders. Unless the "
+            "builders configurations are similar, use multiple "
+            "--bot <builder>:<test> arguments."))
 
   parser.add_option_group(group)