bug#36276: Not found .so files in bundle made by guix pack

[Andréas Livet]

Hi,

I try to bundle scribus with guix pack in order to install it on a 
centos system on which admin sys doesn't want us to install guix.

So I created a tarball with a symlink to '/usr/bin' (don't know it's 
really the recommanded way), this way scribus binary will automatically 
be in the $PATH.

Here is how I created the bundle :

guix pack -S /usr/bin=bin scribus

I tried it on my Xubuntu 18.04 system and it worked like a charm.

But, when deployed on the centos machine, it did not found 
"libQt5Core.so.5" depsite the file exists.

ldd 
/gnu/store/5xqmac50axcgc8vrrn30jvzndjvrqd6a-scribus-1.5.4/bin/.scribus-real 
| grep Qt
    libQt5Xml.so.5 => 
/gnu/store/890yw9i7lcjnnxhlza8r121352xpb1hi-qtbase-5.11.3/lib/libQt5Xml.so.5 
(0x00007f60dd9f6000)
    libQt5Network.so.5 => 
/gnu/store/890yw9i7lcjnnxhlza8r121352xpb1hi-qtbase-5.11.3/lib/libQt5Network.so.5 
(0x00007f60dd7a4000)
    libQt5OpenGL.so.5 => 
/gnu/store/890yw9i7lcjnnxhlza8r121352xpb1hi-qtbase-5.11.3/lib/libQt5OpenGL.so.5 
(0x00007f60dd99a000)
    libQt5PrintSupport.so.5 => 
/gnu/store/890yw9i7lcjnnxhlza8r121352xpb1hi-qtbase-5.11.3/lib/libQt5PrintSupport.so.5 
(0x00007f60dd72b000)
    libQt5Widgets.so.5 => 
/gnu/store/890yw9i7lcjnnxhlza8r121352xpb1hi-qtbase-5.11.3/lib/libQt5Widgets.so.5 
(0x00007f60da93b000)
    libQt5Gui.so.5 => 
/gnu/store/890yw9i7lcjnnxhlza8r121352xpb1hi-qtbase-5.11.3/lib/libQt5Gui.so.5 
(0x00007f60da3a6000)
    libQt5Core.so.5 => not found

I don't understand why it founds libQt5Gui.so.5 and not libQt5Core.so.5 
which is in the same directory !

I tried to copy the .so inside the bin directory, to add qbase lib path 
to $LD_LIBRARY_PATH, doesn't seem to work.

Can't find any further information on guix manual, so I'm asking here.

Thanks in advance for your help,

Andréas