Subject: Re: bug#48907: Debug symbols file name discrepancies

From: Ludovic Courtès <[email-masked]>
Date: Fri, 18 Jun 2021 11:29:54 +0200

Hi,

Maxim Cournoyer <[email-masked]> skribis:

> $ guix build qtdeclarative | xargs -I{} find -L {} -name *libQt5Qml.so.5*
> substitute: updating substitutes from 'http://127.0.0.1:8080'... 100.0%
> substitute: updating substitutes from 'https://ci.guix.gnu.org'... 100.0%
> The following files will be downloaded:
>    /gnu/store/g1gxfbkyxilnx7s6mjdlj697y5n5wazn-qtdeclarative-5.15.2-debug
>    /gnu/store/nvzvrr137qfqsn2875yrs9ilfd12wi96-qtdeclarative-5.15.2
> substituting /gnu/store/g1gxfbkyxilnx7s6mjdlj697y5n5wazn-qtdeclarative-5.15.2-debug...
> downloading from https://ci.guix.gnu.org/nar/lzip/g1gxfbkyxilnx7s6mjdlj697y5n5wazn-qtdeclarative-5.15.2-debug ...
>  qtdeclarative-5.15.2-debug  94.9MiB                            1.2MiB/s 01:21 [##################] 100.0%
>
> The following graft will be made:
>    /gnu/store/djhcai9rixm2j3jlamwdhsgwgidg7w74-qtdeclarative-5.15.2.drv
> applying 2 grafts for /gnu/store/djhcai9rixm2j3jlamwdhsgwgidg7w74-qtdeclarative-5.15.2.drv ...
> grafting '/gnu/store/g1gxfbkyxilnx7s6mjdlj697y5n5wazn-qtdeclarative-5.15.2-debug' -> '/gnu/store/l3h4ka7v3j1yhik0f1phwch08a09p0bx-qtdeclarative-5.15.2-debug'...
> grafting '/gnu/store/nvzvrr137qfqsn2875yrs9ilfd12wi96-qtdeclarative-5.15.2' -> '/gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2'...
> updating '.gnu_debuglink' CRC in '/gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/bin/qml'
> updating '.gnu_debuglink' CRC in '/gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/bin/q
> [...]
> updating '.gnu_debuglink' CRC in '/gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/lib/qt5/qml/QtQuick/Window.2/libwindowplugin.so'
> updating '.gnu_debuglink' CRC in '/gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/lib/qt5/qml/QtTest/libqmltestplugin.so'
> successfully built /gnu/store/djhcai9rixm2j3jlamwdhsgwgidg7w74-qtdeclarative-5.15.2.drv
> /gnu/store/l3h4ka7v3j1yhik0f1phwch08a09p0bx-qtdeclarative-5.15.2-debug/lib/debug/gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/lib/libQt5Qml.so.5.15.2.debug
> /gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/lib/libQt5Qml.so.5.15.2
> /gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/lib/libQt5Qml.so.5
> /gnu/store/pryhgzb6cwnzsskqwldwc6dxr6nwnywf-qtdeclarative-5.15.2/lib/libQt5Qml.so.5.15
>
>
> So far so good.  The file hierarchy under the debug output matches the
> actual shared library file name.  Next, let's verify which qtdeclarative
> shared libraries jami-qt is dynamically linked against:
>
> $ guix build jami-qt | tail -1 | xargs -I{} ldd {}/bin/.jami-qt-real | grep qtdeclarative
>         libQt5QuickWidgets.so.5 => /gnu/store/mjl02yma4r5xjark6d8pp5h2j0a2vccs-qtdeclarative-5.15.2/lib/libQt5QuickWidgets.so.5 (0x00007fb9e38a8000)
>         libQt5Quick.so.5 => /gnu/store/mjl02yma4r5xjark6d8pp5h2j0a2vccs-qtdeclarative-5.15.2/lib/libQt5Quick.so.5 (0x00007fb9dba47000)
>         libQt5QmlModels.so.5 => /gnu/store/mjl02yma4r5xjark6d8pp5h2j0a2vccs-qtdeclarative-5.15.2/lib/libQt5QmlModels.so.5 (0x00007fb9db9c3000)
>         libQt5Qml.so.5 => /gnu/store/mjl02yma4r5xjark6d8pp5h2j0a2vccs-qtdeclarative-5.15.2/lib/libQt5Qml.so.5 (0x00007fb9dae4e000)

This is due to the fact that, when you run ‘guix build jami-qt’, the
grafting derivation dismisses the “debug” output of qtdeclarative, since
jami-qt does not depend on it.  That way it doesn’t have to
build/download and graft qtdeclarative:debug.

Conversely, when you run ‘guix build qtdeclarative’, it grafts both
outputs of qtdeclarative.  Thus, this grafting derivation is different
from the one jami-qt.drv depends on.

This behavior was implemented in commit
482fda2729c3e76999892cb8f9a0391a7bd37119.  Not sure what a good solution
would be.

Thoughts?

Ludo’.