`concurrent.interpreters.Interpreter.exec` propagate `SyntaxError`

Bug report

Bug description:

Hi,

I am testing the concurrent.interpreters feature from Python 3.14rc3 (the latest current rc).

The subinterpreter seems to behave in a surprising way when encountering syntax errors. For example, in the following code:

from concurrent import interpreters

interpr = interpreters.create()

def exec_catching_errors(code: str) -> None:
    try:
        interpr.exec(code)
    except interpreters.ExecutionFailed as e:
        print(f"There was an error: {e}")
    print("The function ends")


exec_catching_errors("print(1/0)")
exec_catching_errors("print 1")  # this is the surprising line

# the whole script dies with an uncaught SyntaxError

• trying to execute print(1/0) causes an interpreters.ExecutionFailed that correctly wraps a ZeroDivisionError.
• trying to execute print 1 causes a bare SyntaxError, whereas I would have expected a subclass of interpreters.InterpreterError wrapping the SyntaxError.

Is this intended behaviour, a bug, or something that simply needs to be better documented?

Thanks

CPython versions tested on:

3.14

Operating systems tested on:

Linux

从 concurrent.interpreters.Interpreter.exec 的实现开始，并在 Python 3.14 上重现报告中的两个代码片段。确定相对于 ExecutionFailed 应如何处理 SyntaxError，然后添加或更新有针对性的测试，使行为明确且一致。