Thankfully, JACK was dropped from the Android build system in version 9.0 Pie. In case you’re stuck with Oreo, here are some tips.
On Android 8.x, JACK needs some extra packages. check with jack-diagnose
In a bare buildroot, these might be missing, so install them:
apt install curl lsof
In a buildroot, if somehow installing the JACK .jar files into ~/.jack-server
fails, run this on the host and bind-mount ~/.jack-server into the target:
./prebuilts/sdk/tools/jack-admin install-server \
./prebuilts/sdk/tools/jack-launcher.jar \
./prebuilts/sdk/tools/jack-server-4.11.ALPHA.jar
(jack-server-4.11.ALPHA.jar might be named differently depending on the version
of android you are building)
Then ensure that ~/.jack-server contains these files:
$ ls ~/.jack-server
jack/ client.jks config.properties server-1.jar server.pem
logs/ client.pem launcher.jar server.jks