git submodule update stuck while running CI build

Problem

While running CI build through gitlab-ci.yml the build gets stuck with the following line

Updating/initializing submodules recursively .....

This issue comes after running a couple of builds and a runner restart is needed . I m using the following lines in my gitlab-ci.yml

  before_script:
    - git submodule sync --recursive
    - git submodule update --init --recursive --remote

Workaround

This problem is likely due to the git credential manager on Windows asking for interactive input. The following job variables can prevent this:

variables:
  GIT_TERMINAL_PROMPT: "0"
  GCM_INTERACTIVE: "Never"

Following the steps in https://docs.gitlab.com/ee/ci/git_submodules.html might help resolve as to why submodules need credentials, but there's not a one-fits-all solution to this.