* doc/guix.texi (Invoking guix time-machine): Document limitation.
* guix/scripts/time-machine.scm (%oldest-possible-commit): New variable.
(guix-time-machine): Raise an error when the channel commit is too old.
Suggested-by: Simon Tournier <zimon.toutoune@gmail.com>
---
doc/guix.texi | 6 ++++++
guix/scripts/time-machine.scm | 23 ++++++++++++++++++++++-
2 files changed, 28 insertions(+), 1 deletion(-)
Toggle diff (86 lines)
diff --git a/doc/guix.texi b/doc/guix.texi
index 1d8ebcd72f..30fef813c0 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -5056,6 +5056,12 @@ Invoking guix time-machine
large number of packages; the result is cached though and subsequent
commands targeting the same commit are almost instantaneous.
+Due to @command{guix time-machine} relying on the ``inferiors''
+mechanism (@pxref{Inferiors}), the oldest commit it can travel to is
+commit @samp{2ca299caf} (``Add (guix inferior) and (guix scripts
+repl).''), dated July 10@sup{th}, 2018. An error is returned when
+attempting to navigate to older commits.
+
@quotation Note
The history of Guix is immutable and @command{guix time-machine}
provides the exact same software as they are in a specific Guix
diff --git a/guix/scripts/time-machine.scm b/guix/scripts/time-machine.scm
index d7c71ef705..36a40a1538 100644
--- a/guix/scripts/time-machine.scm
+++ b/guix/scripts/time-machine.scm
@@ -2,6 +2,7 @@
;;; Copyright © 2019 Konrad Hinsen <konrad.hinsen@fastmail.net>
;;; Copyright © 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2021 Simon Tournier <zimon.toutoune@gmail.com>
+;;; Copyright © 2023 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
@@ -19,13 +20,15 @@
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix scripts time-machine)
+ #:use-module (guix channels)
+ #:use-module (guix diagnostics)
#:use-module (guix ui)
#:use-module (guix scripts)
#:use-module (guix inferior)
#:use-module (guix store)
#:use-module (guix status)
#:use-module ((guix git)
- #:select (with-git-error-handling))
+ #:select (update-cached-checkout with-git-error-handling))
#:use-module ((guix utils)
#:select (%current-system))
#:use-module ((guix scripts pull)
@@ -38,9 +41,16 @@ (define-module (guix scripts time-machine)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
+ #:use-module (srfi srfi-34)
#:use-module (srfi srfi-37)
+ #:use-module (srfi srfi-71)
#:export (guix-time-machine))
+;;; The commit introducing the 'inferiors' mechanism; it is the oldest commit
+;;; that can be travelled to.
+(define %oldest-possible-commit
+ "2ca299caf64489f4e1e665ec1158fb0309b0b565")
+
;;;
;;; Command-line options.
@@ -139,9 +149,20 @@ (define-command (guix-time-machine . args)
(with-git-error-handling
(let* ((opts (parse-args args))
(channels (channel-list opts))
+ (guix-channel (find guix-channel? channels))
(command-line (assoc-ref opts 'exec))
+ (ref (assoc-ref opts 'ref))
+ (checkout commit relation (update-cached-checkout
+ (channel-url guix-channel)
+ #:ref (or ref '())
+ #:starting-commit
+ %oldest-possible-commit))
(substitutes? (assoc-ref opts 'substitutes?))
(authenticate? (assoc-ref opts 'authenticate-channels?)))
+ (unless (memq relation '(ancestor self))
+ (raise (formatted-message
+ (G_ "cannot travel past commit `~a' from July 10th, 2018")
+ (string-take %oldest-possible-commit 12))))
(when command-line
(let* ((directory
(with-store store
--
2.41.0
