Bug 27915

Summary: Cannot handle 8-byte build ID
Product: debugedit Reporter: Matthias Klose <doko>
Component: debugeditAssignee: Not yet assigned to anyone <unassigned>
Status: RESOLVED NOTABUG    
Severity: normal CC: debugedit, mark
Priority: P2    
Version: unspecified   
Target Milestone: ---   
See Also: https://bugs.llvm.org/show_bug.cgi?id=44138
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Attachments: test case

Description Matthias Klose 2021-05-26 09:45:13 UTC 
Created attachment 13471 [details]
test case

seen when building the nageru package in Ubuntu:

full build log at
https://launchpad.net/ubuntu/+source/nageru/2.0.1-3/+build/21476382

$ debugedit --build-id --build-id-seed=nageru/2.0.1-3 debian/nageru/usr/bin/kaeru
debugedit: debian/nageru/usr/bin/kaeru: Unknown DWARF DW_FORM_0x1f20
Cannot handle 8-byte build ID
Comment 1 Mark Wielaard 2021-05-26 12:50:25 UTC 
(In reply to Matthias Klose from comment #0)
> Cannot handle 8-byte build ID

An 8-byte (just 64bits) build ID doesn't make much sense.
It is too small to make sure it is a globally unique identifier.
You need 16 bytes (128 bits) minimum.

This must be a linker bug. Older lld had a bug where they had a "fast" build-id generator that produced such small (useless) build-ids.
Comment 2 Matthias Klose 2021-05-26 14:16:27 UTC 
indeed, the package has a build dependency on lld. But "Older lld" means here LLVM 11 ...
Comment 3 Mark Wielaard 2021-05-26 14:24:00 UTC 
I see there is already an lld bug open against this:
https://bugs.llvm.org/show_bug.cgi?id=44138