py_compile CLI error message missing newline

[bartlomiej-stefanski]

Bug report

Bug description:

When attempting to run py_compile using its CLI (python3 -m py_compile test.py) on file with erroneous indentation, ex:

# test.py
  print("hello world")
# unexpected space characters before `print`

An error will be printed to stderr, but without a newline at the end.

Although the py_compile documentation does not specify the error message format, the lack of newline is unconventional and can lead to unexpected behavior of scripts dependent on it.

The same issue was already raised twice:

• 2005 (2.7) Newline in error output of py_compile.compile #41763
• 2015 (3.4) Python py_compile error message inconsistent and missing newline #67999

in both instances the newline was added thus the lack of one now seems to be unintentional.

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If this is confirmed to be a bug I will attempt to write a fix for it.

CPython versions tested on:

3.12

Operating systems tested on:

Linux