Qt 5.15 and openGL on aarch64
A lot of Qt5 apps that require openGL fail to build as Flatpak on aarch64 or when they do, crash with openGL.
However on the same hardware / OS (Raspberry Pi 400 with RaspberryPi OS 64-bits, aka Debian Buster) they run fine as distribution provided package.
On example I have is FreeCAD.
Looking at the differences I notice that the Flatpak SDK does build Qt with only GLES2 on aarch64 while the Debian package does that for arm 32-bits: https://salsa.debian.org/qt-kde-team/qt/qtbase/-/blob/master/debian/rules#L32
I don't know much about the whole openGL stack but all of this lead me to think that regular openGL should be build on aarch64 as well.
I'll try to see if rebuilding the SDK solve the problem. (if I can do that on the Raspberry Pi 400)
The other issue is that I wonder if that doesn't break the ABI to do so, and if that's the case, when can this be expected to happen. 5.16 release ? There is a new freedesktop-sdk coming in August.
I can provide more details if you need. Let me know.
Update: this is about Qt 5.15