pypy/interpreter/pyparser/test/test_pytokenizer.py::test_f_string[format specifier: double braces]

source = 'f"{x:{{}}b"}\n'
expected = [(7, 'f"', 1, 0, 1, 2), (29, '{', 1, 2, 1, 3), (1, 'x', 1, 3, 1, 4), (14, ':', 1, 4, 1, 5), (8, '', 1, 5, 1, 5), (29, '{', 1, 5, 1, 6), ...]

    @_parametrize("source, expected", _fstring_tests)
    def test_f_string(source, expected):
        lines = source.splitlines(True)
        tks = tokenize(source)
        assert tks[: len(expected)] == [
            Token(
                tk_type,
                value,
                lineno,
                col_offset,
                lines[end_lineno - 1],
                end_lineno,
                end_col_offset,
            )
>           for tk_type, value, lineno, col_offset, end_lineno, end_col_offset in expected
        ]
E       assert [Token(FSTRIN...RACE, {), ...] == [Token(FSTRING...RACE, {), ...]
E         At index 4 diff: Token(LBRACE, {) != Token(FSTRING_MIDDLE, )
E         Use -v to get the full diff

interpreter/pyparser/test/test_pytokenizer.py:796: AssertionError

builder: own-linux-x86-64 build #10880+

test: pypy/interpreter/pyparser/test/test_pytokenizer.py::test_f_string[format specifier: double braces]