Got a little farther by downgrading the flatpak-builder-tools

CONTRIBUTING.rst

@@ -83,8 +83,8 @@ Building the flatpak
 --------------------
 
 - A flatpak-builder environment must be setup on the build machine to do a
-  flatpak build. This includes ``org.gnome.SDK//3.34`` and
-  ``org.gnome.Platform//3.34``.
+  flatpak build. This includes ``org.gnome.SDK//3.36`` and
+  ``org.gnome.Platform//3.36``.
 - The ``flatpak`` folder contains the required files to build a flatpak package.
 - The script ``flatpak_build.sh`` will run the required commands to grab the
   remaining dependencies and build the flatpak.

flatpak/app.sublimemusic.SublimeMusic.json

@@ -1,7 +1,7 @@
 {
   "app-id": "app.sublimemusic.SublimeMusic",
   "runtime": "org.gnome.Platform",
-  "runtime-version": "3.34",
+  "runtime-version": "3.36",
   "sdk": "org.gnome.Sdk",
   "command": "sublime-music",
   "rename-icon": "sublime-music",

flatpak/flatpak-requirements.txt

@@ -19,6 +19,7 @@ python-dateutil==2.8.1
 python-levenshtein==0.12.0
 python-mpv==0.4.6
 requests==2.23.0
+semver==2.10.2
 stringcase==1.2.0
 typing-extensions==3.7.4.2
 typing-inspect==0.6.0

flatpak/flatpak_build.sh

@@ -8,6 +8,10 @@ APPID=app.sublimemusic.SublimeMusic
 rm -rf flatpak-builder-tools
 git clone https://github.com/flatpak/flatpak-builder-tools.git
 
+pushd flatpak-builder-tools
+git checkout 8dd64fc
+popd
+
 python3 ./flatpak-builder-tools/pip/flatpak-pip-generator \
     --requirements-file=flatpak-requirements.txt \
     --output pypi-dependencies