I could not get it to detect my SDK path, so I modified resCompiler to look like this, which I think is maybe closer to the intent of that code:
from distutils.spawn import find_executable
try:
# locate PebbleSDK so we can profit from their code :)
path=os.path.dirname(find_executable('pebble'))
sdk_tools_path = os.path.join(path, '..', 'Pebble', 'tools')
if os.path.exists(os.path.join(sdk_tools_path, 'bitmapgen.py')):
sys.path.append(sdk_tools_path)
import bitmapgen # safest way to convert bitmap resources..
except ImportError as e:
logging.basicConfig(format='[%(levelname)-8s] %(message)s', level=logging.INFO)
logging.fatal('Unable to detect PebbleSDK, make sure it is in your PATH!')
sys.exit(1)