Re: ld compat linker warnings considered harmful

On Thu, 20 Aug 2026, David Holland wrote:

> On Wed, Aug 19, 2026 at 11:42:37PM +0000, RVP wrote:
>
> > I don't get this error at all. The only function that libroken's using from
> > libutil is pidfile(3), so why are those warning being triggered.
>
> Thanks for the simple example; that was sufficient to determine that
> it's being caused by the LTO plugin. As in, if you take the LTO plugin
> material out of the link line, it stops happening.
>

Actually, I believe it's this:

https://github.com/NetBSD/src/commit/d138d9f7e9bad645835c789d42405d05fb3dd84b

Adding the `--copy-dt-needed-entries' behaviour's been lost and put back twice
before:

https://github.com/NetBSD/src/commit/ac4a17f185bbc107fd63d47bf7715b066ca83115
https://github.com/NetBSD/src/commit/d138d9f7e9bad645835c789d42405d05fb3dd84b

All of them to fix what PR lib/57615 wants to do (as this is done on Linux).

In addition to wiz@'s issue, this change also has another unexpected side-effect:

```
$ cat t.c
#include <util.h>

int main(void) {
 	int fd = pidfile("/tmp/my.pid");
 	return fd != 0;
}

$ cc -o t t.c -lroken
```

Don't need to link with `-lutil' at all. Any library which `DT_NEEDED's libutil
will do: libroken, libgssapi, ... Fun!

-RVP

PS. cc'ing rin@, christos@ & joerg@ as they're the ones who put back this change
each time it was lost.