* gnu/machine.scm (roll-back-machine, &deploy-error, deploy-error?)
(deploy-error-should-roll-back)
(deploy-error-captured-args): New variable.
* gnu/machine/ssh.scm (roll-back-managed-host): New variable.
* guix/scripts/deploy.scm (guix-deploy): Roll-back systems when a
deployment fails.
* gnu/services.scm (activation-script): Return a <program-file> rather
than a <scheme-file>.
* gnu/deploy.scm (guix-deploy): Remove handling for '--system'.
(show-help): Remove documentation for '--system'.
(%default-options): Remove default setting for 'system'.
* guix/scripts/deploy.scm (load-source-file): Enumerate and include all
submodules of (gnu machine) when loading the provided deployment
specification.
Ludovic Courtès