Use POLLY_ROOT to detect build.py

appveyor.yml

@@ -63,7 +63,7 @@ install:
   - cmd: set POLLY_VERSION="0.9.0"
   - cmd: appveyor DownloadFile "https://github.com/ruslo/polly/archive/v%POLLY_VERSION%.tar.gz"
   - cmd: cmake -E tar xf "v%POLLY_VERSION%.tar.gz"
-  - cmd: set PATH=%cd%\polly-%POLLY_VERSION%\bin;%PATH%
+  - cmd: set POLLY_ROOT=%cd%\polly-%POLLY_VERSION%
 
   # Python 3 for Polly
   - cmd: set PATH=C:\Python34-x64;%PATH%

jenkins.py

@@ -137,15 +137,22 @@ def run():
           else:
             shutil.rmtree(to_remove)
 
-  build_script = 'build.py'
   if os.name == 'nt':
     which = 'where'
   else:
     which = 'which'
 
-  build_script = subprocess.check_output(
-      [which, 'build.py'], universal_newlines=True
-  ).split('\n')[0]
+  polly_root = os.getenv('POLLY_ROOT')
+  if polly_root:
+    print('Using POLLY_ROOT: {}'.format(polly_root))
+    build_script = os.path.join(polly_root, 'bin', 'build.py')
+  else:
+    build_script = subprocess.check_output(
+        [which, 'build.py'], universal_newlines=True
+    ).split('\n')[0]
+
+  if not os.path.exists(build_script):
+    sys.exit('Script not found: {}'.format(build_script))
 
   print('Testing in: {}'.format(testing_dir))
   os.chdir(testing_dir)