Re: Git clone failures on armv7, was Re: Git core dump checking out main on armv7

From: bob prohaska <fbsd_at_www.zefox.net>
Date: Sun, 23 Jun 2024 14:28:25 UTC
On Sat, Jun 22, 2024 at 06:21:13PM -0700, Mark Millard wrote:
> On Jun 22, 2024, at 16:10, bob prohaska <fbsd@www.zefox.net> wrote:
> 
> 
> Are they both microsd card based? If they are, what if

No, all three were writing to a USB hard disk. The Pi4
running -current the the Pi2 running stable/14 were
using the disk holding root, the Pi2 running -current
was using a disk plugged in and attached at /mnt, but
not part of the root filesystem.  

> a microsd card USB reader/writer is used instead of the
> microsd card slot for booting the microsd card? (This
> might require another microsd card with that has just
> a sufficiently modern bootcode.bin on it to enable the
> USB based boot.)
>

In general, letting git write to usb flash has been a
bad idea for me. It works sometimes, but mechanical
disks seem better-behaved.
 
> I can think of one other type of test that somewhat
> isolates kernel vs. world issues:
> 
> It should be possible to mount the media normally used
> on one of the RPi2B v1.1's on, say, an RPi4B. One could
> then set up enough context to, say, chroot into the
> armv7 file system and try executing the clone in that
> context.
> 

That's physically not hard to do. Just power down the stable/14
Pi2 and plug the Pi2's boot disk into the Pi4.

> The result would be using the RPi4B aarch64 kernel and
> the armv7 world. If that has no problems, then the armv7
> kernel likely has problems that contribute but the armv7
> world would be less likely to.
> 
> Doing this can get into first using the likes of
> (notation presumes use of /mnt at the mount point used
> above):
> 
> # mount -tdevfs devfs /mnt/dev/
> and possibly:
> # mount -tfdescfs none /mnt/fd/
> 
> before doing the likes of:
> 
> # chroot /mnt/
> # # EXPERIMENT HERE
> # exit
>
I didn't realise that armv7 binaries would run under
an aarch64 kernel. Most convenient!
 
> Also, after exiting the chroot session, one would
> do the likes of:
> 
> # umount /mnt/dev/
> and possibly:
> # umount /mnt/fd/
> 
> # umount /mnt/
>
Thank you for the cleanup details!
 
> Note: The RPi4B kernel should not be an older vintage
> than the armv7 world. Also, the RPi4B kernel should not
> be stable/14 based if the armv7 world is main [15]
> based. But a new enough RPi4B main [15] kernel should
> be sufficient for both types of armv7 world.
>

The only Pi4 on hand is running -current. The armv7 system
is stable/14. I'll give it a try tomorrow.  

Thanks for writing!

bob prohaska