On Sun, Sep 1, 2024 at 1:45 PM Gordon Steemson <gsteemso@gmail.com> wrote:
Hello all,

> Date: Fri, 30 Aug 2024 21:27:16 -0500
> From: Rob Browning <rlb@defaultvalue.org>
>
> 3.0.10 does appear to be broken on 32-bit architectures:
> https://buildd.debian.org/guile-3.0
>
> So if that's what you have, you may need to stick with 3.0.9 for now.  I
> plan to downgrade debian/unstable to 3.0.9 this weekend.

Well, it is good if 3.0.10 is broken on ppc32 in general and not only macOS, since then there are higher chances it gets fixed for everyone, as the failure is not supposed to be OS-specific.
 
I did get it to build for 32-bit as part of a multi-architecture ("fat binary") build, using the old Apple GCC.  I don't seem to have needed to do anything special to make it work, though I obviously do need to test whether it will build 32-bit only.  I will report back if any relevant observations come up – as noted, it’s a 13-hour build, so this won’t be immediate.

I am not really an expert re how this works with FAT builds (since it is broken in MacPorts at the moment), but I can imagine ld64 behaving differently when building bi-arch (Apple gcc support building for both in one go).
BTW, interesting that you built it with gcc-4.2. For some reason I had C11 in the portfile, which pulled in gcc-14. I should try old Xcode gcc, maybe that gonna work.