How can I resolve the problem which is indicated in this error report?

Question

Since I upgraded Xcode from 10.1 to 10.3 and macOS from 10.13.3 to 10.14.6 I get this error when compiling my RubyMotion App:

Compile ./app/screens/W-WEITERE/MUSTER/navi/MUSTER_navi1_screen.rb
    Create ./build/iPhoneSimulator-12.4-Development/123capisco.app
      Link ./build/iPhoneSimulator-12.4-Development/123capisco.app/123capisco
Undefined symbols for architecture x86_64:
  "_AVAudioSessionCategoryPlayAndRecord", referenced from:
      _MREP_F4CCBE9F6CA44A048FC85F20CD4B251D in audio_module.rb.o
  "_AVEncoderAudioQualityKey", referenced from:
      _MREP_DFCA252F6BE94535B9A066C31BE62CFB in audio_recorder.rb.o
  "_AVFormatIDKey", referenced from:
      _MREP_DFCA252F6BE94535B9A066C31BE62CFB in audio_recorder.rb.o
  "_AVNumberOfChannelsKey", referenced from:
      _MREP_DFCA252F6BE94535B9A066C31BE62CFB in audio_recorder.rb.o
  "_AVSampleRateKey", referenced from:
      _MREP_DFCA252F6BE94535B9A066C31BE62CFB in audio_recorder.rb.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
rake aborted!
Command failed with status (1): [/Applications/Xcode.app/Contents/Developer...]
/Library/RubyMotion/lib/motion/project/builder.rb:392:in `build'
/Library/RubyMotion/lib/motion/project/app.rb:78:in `build'
/Library/RubyMotion/lib/motion/project/template/ios.rb:128:in `block (2 levels) in <top (required)>'
/Library/RubyMotion/lib/motion/project/template/ios.rb:239:in `block in <top (required)>'
/Users/daniel0/.rbenv/versions/2.4.2/bin/bundle:23:in `load'
/Users/daniel0/.rbenv/versions/2.4.2/bin/bundle:23:in `<main>'
Tasks: TOP => build:simulator
(See full trace by running task with --trace)
➜  123capisco git:(master) ✗

Answer 1

Problem resolved. This code app.frameworks += ['AVFoundation'] was missing in the Rakefile.