> On Feb 18, 2026, at 4:17 AM, Colin Percival <[email protected]> wrote:
>
> On 2/17/26 11:41, Alan Somers wrote:
>> On Tue, Feb 17, 2026 at 12:37 PM Michael W. Lucas <[email protected]> wrote:
>>> This host didn't have kernel debug symbols. I went to install them and
>>> discovered my host needed updates. Thoughtlessly, I grabbed the new
>>> kernel and the new symbols.
>>>
>>> Oops. You can't debug a 15.0 kernel on 15.0p3.
>>>
>>> bucket/var/crash;kgdb -n 0
>>> kgdb: couldn't find a suitable kernel image
>>>
>>> I have a 15.0 boot environment I could boot into, if there's a way to
>>> install the debugging symbols? Or is there a way to pull the old
>>> kernel and debug symbols down on the current BE?
>>>
>>> On dch's advice I tried setting the pkg.conf URL:
>>> url:
>>> "pkg+https://cloudfront.aws.pkgbase.freebsd.org/FreeBSD:15:amd64/base_release_
>>> 0/"
>>> but got:
>>> pkg: No SRV record found for the repo 'FreeBSD-base'
>
> That isn't going to work because pkg+https says "look up SRV records" and the
> cloudfront.aws.pkgbase.freebsd.org endpoint is *what the SRV record points
> at*. You could have used pkg+https://pkg.freebsd.org/, but that wasn't going
> to work anyway since the repo will give you the latest packages (aka the -p3
> kernel).
>
> The older packages are actually still there, but there's no way for you to
> find them.
>
>> You can probably install the symbols from the DVD image. They're in
>> the kernel-dbg.txz dist set. That should work for you, since your
>> crash happened in 15.0. But the same technique wouldn't work if you
>> had crashed at, say, 15.0-p1.
>
> The DVD image is the way to go. Either from kernel-dbg.txz or from the
> pkgbase repo on the DVD image. But as Alan notes, this only works because
> you crashed on the original release.
>
> We should probably consider creating a separate stash of kernel debug packages
> ,about this until now.c
> Oh, a third option is to boot up an EC2 15.0-RELEASE-p1 image ("base" or
> "cloud-init"; "small" doesn't have debug symbols). But I'm guessing you'd
> prefer to look at your panic locally.
I keep all ZFS snapshots of old releases, and retrieve the old kernel and debug
symbols
from them.
Often users report issues with old releases and developers have limited
bandwidth and
probably have newer release while looking into the issue.
I sometime wonder if it is possible to install a base version into a jail, then
update it to
required patched version? Say install 14.3-RELEASE, and update to
14.3-RELEASE-p1 ?
>
> --
> Colin Percival
> FreeBSD Release Engineering Lead & EC2 platform maintainer
> Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
>
>
Best regards,
Zhenlei
