build: use class path bases, not strings

scripts/slave/recipe_modules/syzygy/config.py

Index: scripts/slave/recipe_modules/syzygy/config.py
diff --git a/scripts/slave/recipe_modules/syzygy/config.py b/scripts/slave/recipe_modules/syzygy/config.py
index 4f8cb25857ed68d577f6877a33d60deff2613b32..4313e7a926738675e854d226d1523374dfee9e36 100644
--- a/scripts/slave/recipe_modules/syzygy/config.py
+++ b/scripts/slave/recipe_modules/syzygy/config.py
@@ -4,13 +4,16 @@
 
 import types
 
-from recipe_engine.config import config_item_context, ConfigGroup, Single
+from recipe_engine.config import (
+    config_item_context, ConfigGroup, Single, Static)
 from recipe_engine.config_types import Path
 from . import api as syzygy_api
 
 
-def BaseConfig(**dummy_kwargs):
+def BaseConfig(CHECKOUT_PATH, **dummy_kwargs):
   return ConfigGroup(
+    CHECKOUT_PATH = Static(CHECKOUT_PATH),
+
     official_build = Single(bool, empty_val=False, required=False),
     unittests_gypi = Single(Path, required=False),
     version_file = Single(Path, required=False),
@@ -28,19 +31,19 @@ def BASE(c):
 @config_ctx()
 def syzygy(c):
   c.official_build = False
-  c.unittests_gypi = Path('[CHECKOUT]', 'syzygy', 'unittests.gypi')
-  c.version_file = Path('[CHECKOUT]', 'syzygy', 'SYZYGY_VERSION')
+  c.unittests_gypi = c.CHECKOUT_PATH.join('syzygy', 'unittests.gypi')
+  c.version_file = c.CHECKOUT_PATH.join('syzygy', 'SYZYGY_VERSION')
 
 
 @config_ctx()
 def syzygy_official(c):
   c.official_build = True
-  c.unittests_gypi = Path('[CHECKOUT]', 'syzygy', 'unittests.gypi')
-  c.version_file = Path('[CHECKOUT]', 'syzygy', 'SYZYGY_VERSION')
+  c.unittests_gypi = c.CHECKOUT_PATH.join('syzygy', 'unittests.gypi')
+  c.version_file = c.CHECKOUT_PATH.join('syzygy', 'SYZYGY_VERSION')
 
 
 @config_ctx()
 def kasko_official(c):
   c.official_build = True
-  c.unittests_gypi = Path('[CHECKOUT]', 'syzygy', 'kasko', 'unittests.gypi')
-  c.version_file = Path('[CHECKOUT]', 'syzygy', 'kasko', 'VERSION')
+  c.unittests_gypi = c.CHECKOUT_PATH.join('syzygy', 'kasko', 'unittests.gypi')
+  c.version_file = c.CHECKOUT_PATH.join('syzygy', 'kasko', 'VERSION')