Speculative request for insight

[Johan Engelen]

On Thursday, 17 May 2018 at 09:16:04 UTC, Russel Winder wrote:
> 
> /home/users/russel/Built/lib/libdyaml.so: undefined reference 
> to 
> `_D3std4conv__T7toCharsVii10TaVEQBd5ascii10LetterCasei1TmZQBrFNaNbNiNfmZ6Result5emptyMFNaNbNdNiNfZb'

LDC's macOS Phobos 1.8.0 also doesn't contain
_D3std4conv__T7toCharsVii10TaVEQBd5ascii10LetterCasei1TmZQBrFNaNbNiNfmZ6Result5emptyMFNaNbNdNiNfZb
pure nothrow @property @nogc @safe bool std.conv.toChars!(10, 
char, 1, ulong).toChars(ulong).Result.empty()

but does contain
_D3std4conv__T7toCharsVii10TaVEQBd5ascii10LetterCasei1TlZQBrFNaNbNiNflZ6Result5emptyMFNaNbNdNiNfZb
pure nothrow @property @nogc @safe bool std.conv.toChars!(10, 
char, 1, long).toChars(long).Result.empty()

Looks like the compiler made a wrong template culling decision. 
Are you sure this does not occur with DMD?

> It is the case that the Dub build of the same code completes 
> fine, so there is a hint that it might be an LDC specific issue.

Can you try the Dub build method with LDC and see if that does 
work?

Template instantiation bugs sometimes arise in separate 
compilation cases (what you are doing here). Would be a big help 
if you can dustmite it.

- Johan