bug#52749: G-expressions don't consistently preserve #nil

[Maxime Devos]

Hi,

Philip McGrath schreef op wo 22-12-2021 om 23:25 [-0500]:
> G-expressions currently do not consistently preserve the distinction 
> between #nil and '(), which causes trouble for programs that rely on 
> that distinction. In particular, the issue affects programs that use 
> (guix build json), because that library uses #nil to represent the JSON 
> value `null', whereas it uses '() to represent an empty JSON array.

The constant #nil is only for elisp compatibility and not something
supposed to be used in Scheme code that isn't for Scheme/elisp
compatibility, so this seems more a bug in (guix build json) to me.

Greetings,
Maxime.