bug#59529: fail to re-prompt after mistyped disk encryption passphrase

["François-René Rideau" <fare@mukn.io>]

When booting into an encrypted disk, guix correctly prompts for an
encryption passphrase, but should the passphrase be somehow mistyped
(which happens more often than not for an appropriately long
passphrase on some devices' bad keyboards), guix drops to the scheme
repl, without any obvious way to usefully restart the process. The
only thing left to do is then to reboot and go through the lengthy
BIOS cycle again.

Could guix, like nix, offer the user many attempts to type the passphrase?

Maybe after 3 to 10 failed attempts, or an attempt using an empty
string, then dropping to the debugger makes sense—but even then, could
some message give a hint about how to do anything useful at the repl,
like restarting for instance?

NB: Using guix 437718442ca758a3857702cecfe5c80aa5df272b.

—♯ƒ • François-René Rideau • Co-Founder and President, MuKn.io
“If instead of teaching other people what government should be and
should do, you'd teach yourself what government actually is and does
do, you'd be a libertarian.”