[yocto] Problem baking 'perl' on Debian-unstable

[Henry Hallam]

Hi folks,

I know Debian unstable is not a tested/supported distribution, but it
worked fine for me for the past 6 months until recently, and I figure
we'll want Yocto to work on Debian Stretch when it's released next
year.  I suspect what I'm seeing is a Debian bug rather than a Yocto
one, but I'd love some help tracking it down so I can report it.

I've narrowed the reproducing test case to the following:

* Set up host with an up-to-date Debian unstable distribution on amd64
* Checkout a clean copy of 'poky', either on the 'krogoth' or 'jethro'
branch (I've tried yocto-2.0.0, -2.0.1 and -2.1 as well as the tip of
jethro, krogoth and master)
* source oe-init-build-env
* Edit local.conf to set MACHINE to qemuarm
* bitbake perl

The build fails at the split_and_strip_files function of the
do_package step.  The target binutils
arm-poky-linux-gnueabi-{objcopy,strip} fail to process
.../package/usr/lib/perl/ptest/generate_uudmap because it is an x86-64
executable and those tools are presumably only built to be able to
handle target (ARM) binaries.  I'm not sure whether generate_uudmap is
supposed to be built for native or target architecture.

https://gist.github.com/henryhallam/de0d2c8ac99bab2c6b9f0ecd41dd4c72

I've reproduced this on several different systems running up-to-date
Debian Unstable, and confirmed that everything builds correctly on a
VM running Debian Stable (Jessie).

I'm somewhat at a loss as to how to proceed further.  I did try
rolling back the 'perl' Debian package from its current version
5.22.2-1 to 5.22.1-10 and corresponding dependencies, which made no
difference.  I'm not sure the host system perl is relevant at all,
though.

Any advice appreciated,

Henry