Signal Desktop Builds for Manjaro aarch64

[ninefathom]

Potentially good news: I've managed to get a build to run. Which will, of course, take quite some time to complete

I've been pretty much just taking some of the modifications I had to do for (ungoogled-)chromium/caidao on aarch64 and applied them to the AUR-electron-ozone-PKGBUILD to work around the more obvious x86_64-assumptions. 

Currently at [4684/31344] and ongoing. I'll report back should it succeed at some point (and put the PKGBUILD in my repo).

Here are the gn build flags I used (in addition to importing release defaults), which do differ slightly from AUR's electron-ozone:

Code:

    'blink_symbol_level = 0'
    'link_pulseaudio = true'
    'treat_warnings_as_errors = false'
    'use_gnome_keyring = false'
    'use_ozone = true'
    'ozone_auto_platforms = false'
    'ozone_platform_wayland = true'
    'ozone_platform_x11 = true'
    'use_xkbcommon = true'
    'use_system_libwayland = true'
    'use_system_minigbm = true'
    'use_system_libdrm = true'
    'use_glib = true'
    'use_gtk = true'
    'rtc_use_pipewire=true'

The main thing is that you need component ffmpeg.  I learned that through plain ole' trial and error.  The builds will all complete without it, but until I enabled it, signal-desktop just gave a blank blue window when launched (even if I manually dropped ffmpeg.so into the electron app).  You'll also need the necessary cross-compilers, of course.