[Openembedded-architecture] Changes that switching from smart to dnf will cause

[Alexander Kanavin]

On 02/14/2017 04:29 PM, Richard Purdie wrote:

> We have situations where we simply don't know in advance if a given
> postinst is going to be able to work at rootfs construction time or
> not. As an example, take the fontconfig postinst. This runs under qemu
> emulation. That emulation can work for some arches and not others. We
> don't really want to have to mark things up to indicate which work and
> which don't. Worse, some target optimisations might work and others
> might not.

I found an example where qemu *is* called directly from postinst - in 
eudev and systemd recipes. Unfortunately, they're both broken:


pkg_postinst_eudev-hwdb () {
     if test -n "$D"; then
         ${@qemu_run_binary(d, '$D', '${bindir}/udevadm')} hwdb --update 
--root $D
         chown root:root $D${sysconfdir}/udev/hwdb.bin
     else
         udevadm hwdb --update
     fi
}


If qemu fails, but chown succeeds, then the whole script will succeed, 
and, as a result, it will not get deferred to first boot as it should 
have been. You *do* need to explicitly check whether something (that may 
fail) did indeed fail, and if it did, then you should halt the script 
execution and defer to first boot.

I hope you're now closer to being convinced that this has to be fixed.


Alex