Create a new channel as a copy of main.
Rename main to:
Delete main? This cannot be undone.
config.substitutions = list(config.substitutions) # Enable substituting Clang Sema source directory for TableGen input. config.substitutions.append(('%clang_src_sema_dir', os.path.join(config.clang_src_dir, 'lib', 'Sema')))