Bug report

When you try to serialize a NaN, inf or -inf with json.dumps(..., allow_nan=False), the error messages are inconsistent, depending on whether you use the indent argument or not.

>>> json.dumps(float('nan'), allow_nan=False)
ValueError: Out of range float values are not JSON compliant

>>> json.dumps(float('nan'), allow_nan=False, indent=4)
ValueError: Out of range float values are not JSON compliant: nan

That is because if you don't use indent, the encoding is done in C code here,
but if you use indent, the encoding is done in pure Python code here, and the error messages are different between the two.

Your environment

• CPython versions tested on: 3.11.0
• Operating system and architecture: MacOS 12.6, Apple Silicon

Linked PRs

• gh-99925: Fix inconsistency in json.dumps() error messages #99926