Re: debootrap error

[Jan Kiszka <jan.kiszka@siemens.com>]

On 19.03.19 10:26, Claudius Heine wrote:
> 
> 
> On 19/03/2019 10.09, Jan Kiszka wrote:
>> On 19.03.19 09:01, Claudius Heine wrote:
>>> 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 :)
>>>
>>
>> Ugly... And that call will actually be nop due to how the script works (if it 
>> works at all).
> 
> Well dpkg-reconfigure would be a bit nicer...
> 

Checked, this seems to work (lesson learned: never create a test entry in 
binfmt_misc with magic:mask of 0:0).

Will write a kas patch.

Jan

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