C# Fails with Requested extension org.freedesktop.Sdk.Extension.mono5 not installed
Running Builder 3.30.2 from flatpak
Using the default 'hello world' gnome application template for C#.
The extension is in fact installed, as can see with this flatpak list results:
Ref Options
org.gnome.Builder/x86_64/stable user,current
org.freedesktop.Platform.VAAPI.Intel/x86_64/18.08 user,runtime
org.freedesktop.Platform.html5-codecs/x86_64/18.08 user,runtime
org.freedesktop.Sdk.Extension.mono5/x86_64/18.08 user,runtime
org.gnome.Platform/x86_64/3.28 user,runtime
org.gnome.Sdk.Docs/x86_64/3.28 user,runtime
org.gnome.Sdk.Docs/x86_64/3.30 user,runtime
org.gnome.Sdk/x86_64/3.28 user,runtime
org.gnome.Sdk/x86_64/3.30 user,runtime
The full command which is failing is this one:
flatpak-builder --arch=x86_64 --ccache --force-clean --disable-updates --disable-download --state-dir /home/user/.var/app/org.gnome.Builder/cache/gnome-builder/flatpak-builder --stop-at=testcsharp3 /home/user/.var/app/org.gnome.Builder/cache/gnome-builder/projects/TestCSharp3/flatpak/staging/x86_64-master /home/user/Projects/TestCSharp3/org.gnome.Testcsharp3.json
Any help on how to resolve?