Enabling the WITH_REPRODUCIBLE_BUILD knob for 12.0-REL

[Rodney W. Grimes]

> On 9/10/18 9:51 AM, Rodney W. Grimes wrote:
> >> The FreeBSD base system is a reproducible build[1] with a minor
> >> exception: the build metadata (timestamps, user, hostname, etc.)
> >> included in the kernel and loader.
> >>
> >> With the default, non-reproducible build the kernel ident looks like:
> >>
> >> FreeBSD 12.0-ALPHA5 #4 r338195: Mon Jan 1 10:11:12 EDT 2018
> >>    user at hostname:/path/to/freebsd/src
> >>
> >> and the loader ident:
> >>
> >> FreeBSD/amd64 EFI loader, Revision 1.1
> >> (Mon Jan 1 10:11:12 EDT 2018 user at hostname)
> >>
> >> With reproducible builds enabled the kernel ident looks like:
> >>
> >> FreeBSD 12.0-ALPHA5  r338195
> >>
> >> and the loader ident:
> >>
> >> FreeBSD/amd64 EFI loader, Revision 1.1
> >>
> >> I would like to enable the REPRODUCIBLE_BUILD knob by default for the
> >> 12.0 release, and propose we do this by adding a step to switch the
> >> default to the list of changes[2] that re@ commits to the branch as
> >> part of the release process.
> > 
> > Why not just turn this on and leave it on?
> 
> For kernels not built against a pristine tree the extra info is useful to
> have.  For better or worse, kgdb also parses the path to try to find
> kernel.full (used by e.g. 'kgdb -n last'), so if you remove the path it
> won't be able to find the matching kernel using its current logic.

So this means stable/12 users would have hassles getting kgdb to work?

> crashinfo uses different logic so will still work fine (crashinfo looks
> for all the things matching /boot/*/kernel and tries them all until it finds
> a match).
> 
> -- 
> John Baldwin
> 
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> 

-- 
Rod Grimes                                                 rgrimes at freebsd.org