# Make a local copy of the substitutions.
config.substitutions = list(config.substitutions)

swift_build_sdk_interfaces_base = (r'env SWIFT_EXEC=%%swiftc_driver_plain %r '
                                   r'%%utils/swift_build_sdk_interfaces.py '
                                   % (sys.executable,))

swift_build_sdk_interfaces = swift_build_sdk_interfaces_base + '%mcp_opt'

config.substitutions.insert(0, ('%swift_build_sdk_interfaces_base',
                                swift_build_sdk_interfaces_base))

config.substitutions.insert(0, ('%swift_build_sdk_interfaces',
                                swift_build_sdk_interfaces))

config.suffixes.add('.py')