I have the following script in .gitlab-ci.yml:

stages:
  - build

the-app:
  stage: build
  image: "ghcr.io/cirruslabs/flutter:3.10.3"
  variables:
    JAVA_VERSION: "17"
    JAVA_DIST: "adopt"
  before_script:
    - apt-get update && apt-get install -y openjdk-17-jdk
    - export PATH="$PATH:$HOME/.pub-cache/bin"

  script:
    - cd mobile_app
    - flutter doctor
    - flutter pub get
    - make build_apk_debug

I receive the following error on flutter doctor step:

[!] Network resources
    ✗ A network error occurred while checking "https://pub.dev/": Failed host lookup: 'pub.dev'

Is there a specific Gitlab project settings which makes this fail ? What else could be the cause of this error ?