base kernel to build fedora

[Tom Lane]

Genes MailLists <lists at sapience.com> writes:
> On 05/23/2010 02:25 PM, Mike McGrath wrote:
>> I don't think anyone thinks rebuilding the builders every 6 months (and
>> fixing all the bugs that comes with that) is a good use of their time.

>  But a release really  should be boot strapped with itself once when it
> gets stable enough .. or at least built with Fedora N-1 as someone else
> suggested.

I still carry the scars from when mysql stopped building in brew, a
couple years ago.  Not just rawhide, but brew in general.  Eventually
(after a couple months of bewilderment) it emerged that the build
machines had been migrated from RHEL4 to RHEL5 kernels, and on the PPC
machines that entailed a change of page size, and mysql had an obscure
dependency on the page size.  So even though brew was building inside
version-specific buildroots, things broke.

So I'm firmly on the side of "do not change the build machines' kernels
often".  Every time you do it, you not only risk breaking the current
branch builds, but past branches.  The consequences for reproducibility
and wasted developer time are enormous.

What we need is not "fedora N is built on fedora N", but "we know what
fedora N is built on, and it *won't* change midstream".  The notion of
rebasing the build machines at some point approaching release is beyond
stupid.

I could maybe buy "fedora N is built on fedora N-1", but there are two
problems with that: first, you'd need a separate build farm for every
branch, and second, fedora N-1 is still a moving target for much of the
life of fedora N.

			regards, tom lane