Install flatpak and flatpak-builder, add the Flathub remote and
install the Gnome runtime and SDK along with the Freedesktop OpenJDK 11 extension:
sudo dnf install flatpak flatpak-builder flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo flatpak install flathub org.gnome.Platform//3.32 org.gnome.Sdk//3.32 org.freedesktop.Sdk.Extension.openjdk11
Build JDK Mission Control from source.
Place jmc/target/products/org.openjdk.jmc-linux.gtk.x86_64.tar.gz into this directory.
Build the JMC Flatpak and export to a local repo:
flatpak-builder --repo repo build org.openjdk.Jmc.json --force-clean
To run this Flatpak, execute:
flatpak-builder --run build org.openjdk.Jmc.json jmc
Install from local repository:
flatpak --user remote-add --no-gpg-verify jmc-local repo flatpak --user install jmc-local org.openjdk.Jmc
Run the installed Flatpak:
flatpak run org.openjdk.Jmc
Desktop file:
desktop-file-validate org.openjdk.Jmc.desktop
Appdata file:
appstream-util validate-relax org.openjdk.Jmc.appdata.xml