Re: debootrap error

[Claudius Heine <claudius.heine.ext@siemens.com>]

On Tue, 2019-03-19 at 08:51 +0100, Jan Kiszka wrote:
> On 19.03.19 08:22, Claudius Heine wrote:
> > Hi Suzuki-san,
> > 
> > On 19/03/2019 06.18, akihiro27.suzuki@toshiba.co.jp wrote:
> > > Hi,
> > > 
> > > > > That is how my qemu-arm setting looks like. Do you have a
> > > > > differentqemu path?
> > > > > 
> > > > > $ cat /proc/sys/fs/binfmt_misc/qemu-arm
> > > > > enabled
> > > > > interpreter /usr/bin/qemu-arm-static
> > > > > flags: OCF
> > > > > offset 0
> > > > > magic 7f454c4601010100000000000000000002002800
> > > > > mask ffffffffffffff00fffffffffffffffffeffffff
> > > My qemu-arm setting is as follows:
> > > 
> > >      $ cat /proc/sys/fs/binfmt_misc/qemu-arm
> > >      enabled
> > >      interpreter /usr/bin/qemu-arm
> > >      flags: OC
> > >      offset 0
> > >      magic 7f454c4601010100000000000000000002002800
> > >      mask ffffffffffffff00fffffffffffffffffeffffff
> > > 
> > > According to this, the interpreter path was not same.
> > > My machine used /usr/bin/qemu-arm but Claudius's machine used 
> > > /usr/bin/qemu-arm-static.
> > > 
> > > If the first place, my machine didn't have /usr/bin/qemu-arm-
> > > static.
> > > So, I installed qemu-user-static as follows:
> > > 
> > >      $ sudo aptitude install qemu-user-static
> > >      [sudo] password for akihiro:
> > >      The following NEW packages will be installed:
> > >        qemu-user-static{b}
> > >      0 packages upgraded, 1 newly installed, 0 to remove and 0
> > > not upgraded.
> > >      Need to get 10.0 MB of archives. After unpacking 101 MB will
> > > be used.
> > >      The following packages have unmet dependencies:
> > >       qemu-user-static : Conflicts: qemu-user-binfmt but 
> > > 1:2.11+dfsg-1ubuntu7.10 is installed
> > >       qemu-user-binfmt : Conflicts: qemu-user-static but 
> > > 1:2.11+dfsg-1ubuntu7.10 is to be installed
> > >      The following actions will resolve these dependencies:
> > >           Remove the following packages:
> > >      1)     qemu-user-binfmt [1:2.11+dfsg-1ubuntu7.10 (bionic-
> > > updates, now)]
> > >      Accept this solution? [Y/n/q/?] Y
> > >      The following NEW packages will be installed:
> > >        qemu-user-static
> > >      The following packages will be REMOVED:
> > >        qemu-user-binfmt{a}
> > >      0 packages upgraded, 1 newly installed, 1 to remove and 0
> > > not upgraded.
> > >      Need to get 10.0 MB of archives. After unpacking 101 MB will
> > > be used.
> > >      Do you want to continue? [Y/n/?] Y
> > >      Get: 1 http://ftp.jaist.ac.jp/pub/Linux/ubuntu bionic-
> > > updates/universe 
> > > amd64 qemu-user-static amd64 1:2.11+dfsg-1ubuntu7.10 [10.0 MB]
> > >      Fetched 10.0 MB in 1min 5s (155 kB/s)
> > >      (Reading database ... 299683 files and directories currently
> > > installed.)
> > >      Removing qemu-user-binfmt (1:2.11+dfsg-1ubuntu7.10) ...
> > >      Selecting previously unselected package qemu-user-static.
> > >      (Reading database ... 299683 files and directories currently
> > > installed.)
> > >      Preparing to unpack 
> > > .../qemu-user-static_1%3a2.11+dfsg-1ubuntu7.10_amd64.deb ...
> > >      Unpacking qemu-user-static (1:2.11+dfsg-1ubuntu7.10) ...
> > >      Setting up qemu-user-static (1:2.11+dfsg-1ubuntu7.10) ...
> > >      Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
> > > 
> > > After that, I checked my qemu-arm setting.
> > > The interpreter path has been changed to /usr/bin/qemu-arm-static 
> > > as below:
> > > 
> > >      $ cat /proc/sys/fs/binfmt_misc/qemu-arm
> > >      enabled
> > >      interpreter /usr/bin/qemu-arm-static
> > >      flags: OC
> > >      offset 0
> > >      magic 7f454c4601010100000000000000000002002800
> > >      mask ffffffffffffff00fffffffffffffffffeffffff
> > > 
> > > After that, I built board-bbb.yml as below, and it succeeded!
> > > 
> > >      $ ./kas-docker --isar build kas.yml:board-bbb.yml
> > > 
> > > The root cause of this error is that my machine was not using
> > > statically linked user mode qemu binaries?
> > 
> > Well the docker container has the 'qemu-user-static' files
> > installed as a 
> > dependency of qemu-debootstrap. The dynamic linking version would
> > not work here, 
> > because qemu-deboostrap will copy just the one binary to the
> > bootstrapped rootfs 
> > before chrooting into it. The binfmt_misc settings needs to point
> > to the qemu 
> > static binary that was copied to the rootfs for this to work. The
> > error of 
> > course is pretty misleading and stumbled over that very often
> > myself.
> > 
> > And what your problem shows as well is that the call of 'update-
> > binfmts 
> > --enable' (which happens in the docker entry point script) does not
> > seem to fix 
> > the path.
> 
> ...which is good to know. Maybe it gets tricked by something being
> enabled 
> already. But I thought I tested this. Anyway, I guess we need to
> study that 
> script /wrt how to achieve some reliable rewriting of the settings.

Well you could just call '/var/lib/dpkg/info/qemu-user-static.postinst' 
from the docker entry point :)