```
===> Compiling emqx_machine
===> Compiling src/user_default.erl failed
src/user_default.erl:{24,14}: can't find include lib "emqx_dashboard/include/emqx_dashboard.hrl"; Make sure emqx_dashboard is in your app file's 'applications' list
==> emqx_mix
** (Mix) Could not compile dependency :emqx_machine, "/github/home/.mix/elixir/1-14/rebar3 bare compile --paths /__w/emqx/emqx/_build/emqx/lib/*/ebin" command failed. Errors may have been logged above. You can recompile this dependency with "mix deps.compile emqx_machine", update it with "mix deps.update emqx_machine" or clean it with "mix deps.clean emqx_machine"
make: *** [Makefile:276: emqx-elixir] Error 1
```
By treating the apps in the umbrella as dependencies to be managed and
built by rebar3, we can simplify the maintenance of the release, at
the cost of increased build times: using Mix as before, it could track
changed files better than using rebar. But the complexity and
possibility of discrepancies make it using rebar much more compelling.
Ilya Averyanov