Python compiled with UCS2 while UCS4 is used in virtually every Linux distro

[aruiz]

UCS4 is a requirement for some 3rd party apps and I came across with the fact that the freedesktop runtime is built with UCS2 (the default in the Python sources)

Given that this is an ABI incompatible change I tried to investigate if there where any Flatpaks with CPython 2 modules that referred to UCS2 symbols, I'm attaching a list of those for the flathub and gnome repos.

I'm attaching the list of ELF objects linking to UCS2. I guess the only other risk here is an app dlopening and accessing those symbols manually, though chances are slim that's happening for this symbol family inside CPython specifically.

flathub.ucs2.txt gnome.ucs2.txt

[aruiz]

Summarizing from earlier, the apps affected are:

MyPaint (flathub)
Inkscape (flathub)
Flowblade (flathub)
Picard (flathub)
Digital (flathub)
d-feet (gnome)

And the runtimes shipping Python2.7 with UCS2 (all in flathub):

org.kde.Platform
org.freedesktop.Platform
org.freedesktop.Platform.Compat32
org.freedesktop.BasePlatform
org.gnome.Platform
org.gnome.Sdk
org.kde.Sdk
org.freedesktop.Sdk
org.freedesktop.BaseSdk

[aruiz]

For reference in case I compiled the list wrong, these are the scripts I ran to generate the list ( basically find ELF files in all flatpaks/runtimes & objdump), I ran this after installing all apps for both flathub and gnome repos on the flatpak dir:

for i in `find . -name active` ; do find $i/ -type f -exec file {} + | grep -i ELF | cut -d ":" -f 1 ; done > /tmp/actives.gnome
for i in `cat /tmp/actives.gnome` ; do if Foo=`ldd $i | tr "\n" " " | grep libpython2` ; then echo $i ; fi ; done > /tmp/actives.gnome.py2
for i in `cat /tmp/actives.gnome`; do if Foo=`objdump -T $i | grep UCS2` ; then echo $i ; objdump -T $i | grep UCS ; fi;done > /tmp/actives.gnome.py2.ucs2

[alexlarsson]

I believe these are all at least queued for building now.

[aruiz]

It seems to me like d-feet was not rebuilt, I don't see an update avaialable on my system at least though the runtime is new so it's broke atm.

[TingPing]

@aruiz Assuming you meant d-feet on flathub I just triggered a rebuild.

[aruiz]

yep!