pypy/module/_io/test/test_bufferedio.py::AppTestBufferedReaderWithThreads::()::test_bufio_write_through

self = <pypy.interpreter.typedef.W_ObjectObjectUserDictWeakrefable object at 0x0000000143c98020>

    def test_bufio_write_through(self):
            import _io as io
            # Issue #21396: write_through=True doesn't force a flush()
            # on the underlying binary buffered object.
            flush_called, write_called = [], []
            class BufferedWriter(io.BufferedWriter):
                def flush(self, *args, **kwargs):
                    flush_called.append(True)
                    return super().flush(*args, **kwargs)
                def write(self, *args, **kwargs):
                    write_called.append(True)
                    return super().write(*args, **kwargs)
    
            rawio = io.BytesIO()
            data = b"a"
            bufio = BufferedWriter(rawio, len(data)*2)
>           textio = io.TextIOWrapper(bufio, encoding='ascii',
                                      write_through=True)
E           (application-level) LookupError: unknown encoding: ascii

[/Users/matti/build-worker-arm64/own-macos-arm64/build/pypy/module/_io/test/test_bufferedio.py:380]:17: LookupError

builder: own-macos-arm64 build #1363+

test: pypy/module/_io/test/test_bufferedio.py::AppTestBufferedReaderWithThreads::()::test_bufio_write_through