a mysterious linking error introduced by import a library

[Johann]

On Saturday, 14 October 2023 at 17:58:27 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
> This may be a simple case of template emission eliding.
>
> Did you try ``-fall-instantiations`` inside of a dflags 
> directive?

Yeah, that works perfectly, thank you a lot.

> This may be a simple case of template emission eliding.

So is this a bug in gdc? And what is a template emission eliding? 
I have never heard of it before.