Flutter analyze / build fails in GitHub action

When the following action is run, it fails on flutter analyze. If I remove it, it fails later on flutter build. Both commands work fine locally. I understand the message, but fail to grasp what might be wrong with the package path.

GitHub action error:

  flutter analyze
  shell: /bin/bash -e {0}
  env:
    JAVA_HOME_12.0.2_x64: /opt/hostedtoolcache/jdk/12.0.2/x64
    JAVA_HOME: /opt/hostedtoolcache/jdk/12.0.2/x64
    JAVA_HOME_12_0_2_X64: /opt/hostedtoolcache/jdk/12.0.2/x64
    FLUTTER_HOME: /opt/hostedtoolcache/flutter/1.22.5-stable/x64
Analyzing myApp...                                            

  error • Target of URI doesn't exist: 'package:myApp/app.dart' • lib/main.dart:7:8 • uri_does_not_exist
  error • The function 'App' isn't defined • lib/main.dart:38:16 • undefined_function

2 issues found. (ran in 18.4s)
Error: Process completed with exit code 1.

Action source:

name: Flutter Android Test and Build

on:
  push:
    branches: [master]
  pull_request:
    branches: [master]

jobs:
  build_android:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2
      - name: Setup Java
        uses: actions/setup-java@v1
        with:
          java-version: "12.x"
      - name: Setup Flutter
        uses: subosito/flutter-action@v1
        with:
          flutter-version: "1.22.5"
      - name: Install Flutter dependencies
        run: flutter pub get
      - name: Format files
        run: flutter format --set-exit-if-changed .
      - name: Analyze code
        run: flutter analyze
      - name: Run tests
        run: flutter test
      - name: Build Android
        run: flutter build apk