Pulling from private repository without known_hosts hangs forever

[Guillaume Beuzeboc]

Having a part source pulling from private repo without known_hosts (--bind-ssh passed) hangs until I press a key in the terminal.
It appears that the Yes/No question from git is hidden by the snapcraft progress line.
Snapcraft should return an error or the input question.

To reproduce:

snapcraft.yaml:

name: nope
base: core22
version: '0.1'
summary: Nope
description: |
  Nope

grade: devel
confinement: strict

parts:
  my-part:
    plugin: python
    source: <email address hidden>:nope/doesnt_exist.git

-----------------

logs:

Starting Snapcraft 8.0.2
Logging execution to '.../.local/state/snapcraft/log/snapcraft-20240212-112649.931680.log'
Running on amd64 for amd64
Launching instance...
Starting instance
Starting Snapcraft 8.0.2
Logging execution to '/tmp/snapcraft.log'
Running on amd64 for amd64
Initializing parts lifecycle
Installing build-packages
Installing build-snaps
The authenticity of host 'github.com (140.82.121.3)' can't be established.
ED25519 key fingerprint is SHA256:+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU.
This key is not known by any other names
Pulling my-part - (309.9s)
Pulling my-part # <--- Hit enter otherwise it hangs
Failed to pull source: command ['git', 'clone', '--recursive', '<email address hidden>:nope/doesnt_exist.git', '/root/parts/my-part/src'] exited with code 128.
Make sure sources are correctly specified.
Failed to execute pack in instance.
Recommended resolution: Run the same command again with --debug to shell into the environment if you wish to introspect this failure.
Full execution log: '.../.local/state/snapcraft/log/snapcraft-20240212-112649.931680.log'