/e/ build for z3c is broken

/e/ version: v0.16
Device model(s): z3c

Summary

@rhunault reported in Telegram that the build for device z3c is broken

Romain HUNAULT, [14 Apr 2021 at 09:11:08]:

Hi! @petefoth I was able to test z3c, and I got an error

FAILED:

packages/apps/FMRadio/Android.mk: error: "FMRadio (APPS android-arm) missing libfmjni (SHARED_LIBRARIES android-arm)"

You can set ALLOW_MISSING_DEPENDENCIES=true in your environment if this is intentional, but that may defer real problems until later in the build. build/make/core/main.mk:972: error: exiting from previous errors.

The problem

Steps to reproduce

Run a build using CI/CD

What is the current behavior?

Build fails - see summary

What is the expected correct behavior?

Build should succeed, no manifest needed. This device is officially supported by LineageOS, ad should build without needing a local manifest

Technical informations

Two things to look at to find out what has broken the build:

Permission changes on some /e/ gitlab repos: several repos in the e / Devices group were recently made private. Is it possible that tgis has caused needed files to nit be visible to the build?
Changes made by /e/ to FM radio app or libraries: I needed to add the LineageOS/android_hardware_broadcom_fm repo to the manifest for suzuran (before it became an official /e/ device) when the maintainer of the upstream unofficial LOS-17.1 ROM added FM library back to his ROM (in this commit. Is it possible that /e/ has made some changes recently involving the FM Radio app or the libraries it uses?

I am not in a position to investigate either of these points as I don't have sufficient access to /e/ resources.

Solutions

Workaround

Adding a local manifest may work around the problem, but it does not explain why the build started to fail

Possible fixes

Find the root cause of the build failure: what was the change that broke the build?