Flatpak notes:

The plugin requires JUCE to build and to run Projucer. For some unknown reasons Projucer fail within flatpak build, but not when run in the build sandbox. So we ship the Makefile (that contain some changes too) and the JuceLibraryCode.

Source/GitCommitId.h is generated by us (Projucer would)

• JUCE is the lv2 port recommended by upstream, to build LV2 support.
• lv2.patch patches the build system.
• juce-path.patch patches JUCE to not use /opt but FLATPAK_DEST string literal. This is required for to locate the presets

Known bugs

Preset won't be saved because of TheWaveWarden/odin2#322

That assumes a world writable /opt/odin2 (now FLATPAK_DEST/odin2).