Re: [gentoo-releng] Uclibc chroots and catalyst

[Anthony G. Basile]

On 12/14/15 1:56 AM, Joshua Kinard wrote:
> I am curious to know if anyone has had any odd issues with using Gentoo's
> releng tool, catalyst, to build Uclibc-based stages before.
>
> I was attempting to resurrect MIPS-III, big-endian stages once more using an
> old ~2012 mips3 seed stage that Anthony Basile put together a while back.  I
> started by manually updating the seed to be current (sans ncurses-6.x), and
> that all worked out fine.  I then fed that seed stage into Catalyst to build a
> new stage1, and that also worked fine.
>
> But when I went to run the stage2 spec, it failed due to bash generating a
> segfault via an attempted NULL pointer dereference.  So I manually tested by
> attempting to chroot into the /tmp/stage1root directly, and that's also
> segfaulting.  I can run other executables within the stage1root via chroot
> directly, but it appears that anything linked to ncurses is triggering a segfault.
>
> The original stages were built with gcc-5.3, so I fell back to gcc-4.8.5, but
> the segfaults are still happening.  I forced the stage1root to upgrade to
> ncurses-6.0, but that isn't working either.  I manually remerged bash by
> setting ROOT="/tmp/stage1root", but it's linking against /lib/libncurses.so.5
> from the seed root instead of /lib/libncurses.so.6 in the stage1root.
>
> Not sure how to work around this.  Everything in the seed root works fine.  If
> I manually merge select packages into a different $ROOT (uclibc, ncurses, bash,
> readline, libiconv), then copy libgcc_s.so into $ROOT/lib manually, I can
> execute bash there just fine.  So part of the problem may also be in how
> catalyst's stage1 script is merging the packages into $ROOT.
>
> Thoughts?
>

because mips is ~arch we are always building the cutting edge which is
going to get you into trouble.  without knowing what's cauing the seg
fault, its hard to proceed.  you can `strace chroot /path <cmd>` but
this may bog down in some heavy debugging.  i'd just start with the
original stage, keep updates back by masking in /etc/portage and
emerging that way.  take a look in the releng git repo I have some
scripts for automating stage1-2-3 with a customized /etc/portage
directory.  putting stuff in /etc/portage for our stage's is evil, but
its sometimes a necessary evil.  (vapier opened a bug about it.)

-- 
Anthony G. Basile, Ph.D.
Gentoo Linux Developer [Hardened]
E-Mail    : blueness@g.o
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