gdc 12.1: undefined references when linking separately compiled files

[Johan]

On Saturday, 28 May 2022 at 22:23:34 UTC, kdevel wrote:
> On Saturday, 28 May 2022 at 15:10:25 UTC, Steven Schveighoffer 
> wrote:
> [...]
>> Is this specific to gdc, or does it happen for other compilers 
>> as well?
>
> The former.

Please check the dlang versions of all compilers. The template 
emission scheme is changing quite often between versions, indeed 
leading to linking problems with separate compilation and complex 
template instantiation trees (one of the main compiler upgrade 
issues at Weka, with LDC).

-Johan