here the (admitteldy hacky) steps to reproduce getting briar-gtk alpha flatpak to work on librm5_devkit aarch64

patched briar headless

cloned briar repo applied two patches:

+++ b/bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java
@@ -192,7 +192,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
                // Load the settings
                settings = callback.getSettings();
                // Install or update the assets if necessary
-               if (!assetsAreUpToDate()) installAssets();
+               //if (!assetsAreUpToDate()) installAssets();
                if (cookieFile.exists() && !cookieFile.delete())
                        LOG.warning("Old auth cookie not deleted");
                // Start a new Tor process


+++ b/bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPluginFactory.java
@@ -82,13 +82,13 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
        @Override
        public DuplexPlugin createPlugin(PluginCallback callback) {
                // Check that we have a Tor binary for this architecture
-               String architecture = null;
-               if (isLinux()) {
-                       String arch = System.getProperty("os.arch");
-                       if (arch.equals("amd64")) {
-                               architecture = "linux-x86_64";
-                       }
-               }
+               String architecture = "linux-aarch64";
+               //if (isLinux()) {
+               //      String arch = System.getProperty("os.arch");
+               //      if (arch.equals("amd64")) {
+               //              architecture = "linux-x86_64";
+               //      }
+               //}
                if (architecture == null) {
                        LOG.info("Tor is not supported on this architecture");
                        return null;

compiled briar-headless as also described in http://4g375hpowkjyopwa7c5lm7f4ovzhceezvscm342uklflfpl3mcxxhxyd.onion/briar_headless_on_librem5_devkit.html

briar-gtk build flatpak

git cloned: https://code.briarproject.org/briar/briar-gtk git submodule update --init built flatpak as advertised via: flatpak-builder --install-deps-from=flathub --user --install --force-clean --ccache flatpak-builddir app.briar.gtk.json

run shell in flatpak container

flatpak run --command=sh app.briar.gtk

first replacing briar headless with the patched version for aarch64 cp /home/purism/dl/briar/briar-headless/build/libs/briar-headless.jar /home/purism/.local/share/flatpak/app/app.briar.gtk/aarch64/master/active/files/briar/briar-headless.jar

starting briar headless inside the flatpak java -jar /app/briar/briar-headless.jar

which complains about the not visible (from flatpak perspective) distro tor dependencies. so copy dependencies into flatpak as well:

libevent-2.1.so.6: cp /usr/lib/aarch64-linux-gnu/libevent-2.1.so.6.0.2 /home/purism/.local/share/flatpak/runtime/org.gnome.Platform/aarch64/3.36/active/files/lib/aarch64-linux-gnu/libevent-2.1.so.6

libzstd.so.1: cp /usr/lib/aarch64-linux-gnu/libzstd.so.1.3.8 /home/purism/.local/share/flatpak/runtime/org.gnome.Platform/aarch64/3.36/active/files/lib/aarch64-linux-gnu/libzstd.so.1

with that briar-headless runs fine.

briar-gtk python key error

python key error, so I disabled the two lines of code:

remove/comment-out lines 30 and 31 of /home/purism/.local/share/flatpak/app/app.briar.gtk/aarch64/master/active/files/lib/python3.7/site-packages/briar_wrapper/models/contacts.py