Fixes a regression introduced in
0642838b2e.
* gnu/services/herd.scm (invoke-action): Explain that we get a list of
results.
(current-services): Expect a list of result and use the first one.
(unload-service, %load-file, eval-there): Likewise.
Previously the match expression case for a successful response
(where error is #f) required that the result component contained a list with a
single element.
As far as I see when looking at the responses from the shepherd, this is not
normally the case. Therefore, to avoid treating successful responses as
errors, make the match requirement more permissive, accepting any value.
* gnu/services/herd.scm (invoke-action): Change match condition for ok responses.
* gnu/services/herd.scm (<live-service>): New record type.
(current-services): Change to return a single value: #f or a list of
<live-service>.
* guix/scripts/system.scm (call-with-service-upgrade-info): Adjust
accordingly.
* gnu/tests/base.scm (run-basic-test)["shepherd services"]: Adjust
accordingly.
This makes (gnu services herd) independent of (guix ui).
* gnu/services/herd.scm (&shepherd-error, &service-not-found-error)
(&action-not-found-error, &action-exception-error)
(&unknown-shepherd-error): New error condition types.
(report-action-error): Remove.
(raise-shepherd-error): New procedure.
(display-message): Do not use 'info' and '_'.
(invoke-action): Use 'raise-shepherd-error' instead of
'report-action-error'. Do not use 'warning'.
(current-services): Do not use 'warning'.
* guix/scripts/system.scm (with-shepherd-error-handling): New macro.
(report-shepherd-error, call-with-service-upgrade-info): New
procedures.
(upgrade-shepherd-services): Use it.
Before that 'open-connection' would return #f, and thus
'current-services' would return a single #f value when its continuation
expects two.
Reported by calher on #guix.
* gnu/services/herd.scm (open-connection): Rethrow system-error
exceptions.
(with-shepherd): Expect CONNECTION to always be true; remove useless
'dynamic-wind'.
* guix/scripts/system.scm (warn-on-system-error): New macro.
(upgrade-shepherd-services): Wrap body in 'warn-on-system-error'.
Partly fixes <http://bugs.gnu.org/22039>.
* gnu/services/herd.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* gnu/services/shepherd.scm (shepherd-service-canonical-name): New
procedure.
(shepherd-service-file): Export.
* guix/scripts/system.scm (upgrade-shepherd-services): New procedure.
(switch-to-system): Use it.
* guix/ui.scm (info): New procedure.
* doc/guix.texi (Invoking guix system): Mention system services.
