ssh_askpass on 'vc-update'

[Gabriel]

I have some git repositories setup with SSH-key access. When I run
'vc-update', it asks my password with "ssh_askpass", but since
'vc-update' runs in Compilation mode, it gets stuck. The 'compile'
commands accepts an argument to run in comint-mode, which can grab the
user password, but currently the 'vc-update' cannot run in
comint-mode. Probably other vc related commands may have this same
issue, but since 'vc-update' is the first thing I run, it's the only
issue I've found so far.

Is there any way to make 'vc-update' grab the user password for cases
like this one ? Is 'vc-update' lacking this feature ?

Looking forward for feedbacks on this matter.
Rergards,
Gabriel