[Dwarf-discuss] DWARF Package File (.dwp) .debug_dwp ID proposal

[Mark Wielaard]

On Tue, 2026-01-20 at 13:44 -0800, David Blaikie wrote:
> Fair enough - thanks for the context.
> I haven't seen _sup used/not familiar with its finer points.

The supplementary DWARF files are an standardization of the similar dwz
alt/multi file idea. dwz can now produce those when given --dwarf-5:

  -5, --dwarf-5       Emit DWARF 5 standardized supplementary object
                      files instead of GNU extension .debug_altlink.

>  Consistency doesn't seem so bad, even if it's with what seems like
>  a fairly underused/old feature so maybe the design could be revisited.

I picked the existing format for consistency and because it described a
similar (possibly many) debug object file to a supplemental/package
file using a naming hint and a checksum/identifier.

> Would've thought it'd be nice to integrate it with buildID and/or with debuginfod...

O, the idea actually came up because of a proposed patch to support dwp
files by debuginfo:
https://inbox.sourceware.org/elfutils-devel/20260121051659.GE312@redhat.com/T/
Maybe I should have referenced that from the start, but the discussion
is not just focused on identifying DWP files, so might be distracting
from the concrete proposal.

Cheers,

Mark