On 20-02-2023 11:06, Ludovic Courtès wrote:
> [...]
> The “Multiple invocations” bit isn’t in libgc 8.0.4.  Which version are
> you looking at?

Commit 151b49a5302eea89ffd9efd9cdb82b75ac4f5d35 (include/gc/gc.h).
Looking at the changelog, that part is there since at least 8.0.6:

[...]
* Refine GC_INIT documentation about its multiple invocation

As it only a documentation change (going by the changelog), possibly the 
same behaviour existed in libgc 8.0.4 too.

Greetings,
Maxime.