$ cat up028.py 
def f(x):
    for e in x,:
        yield e

$ ruff --isolated check --select UP028 --unsafe-fixes --fix up028.py

error: Fix introduced a syntax error. Reverting all changes.

This indicates a bug in Ruff. If you could open an issue at:

    https://github.com/astral-sh/ruff/issues/new?title=%5BFix%20error%5D

...quoting the contents of `up028.py`, the rule codes UP028, along with the `pyproject.toml` settings and executed command, we'd be very appreciative!

up028.py:2:5: UP028 Replace `yield` over `for` loop with `yield from`
  |
1 |   def f(x):
2 | /     for e in x,:
3 | |         yield e
  | |_______________^ UP028
  |
  = help: Replace with `yield from`

Found 1 error.
[*] 1 fixable with the --fix option.