[bug#75981,(WIP),v1,1/4] Add 'guix fork create'.

Message ID 2a950d7e5c42768724d1c8fe3bcea3ff54fb81bd.1738357415.git.45mg.writes@gmail.com
State New
Headers
Series Add 'guix fork'. |

Commit Message

45mg Jan. 31, 2025, 9:18 p.m. UTC
* guix/scripts/fork.scm, guix/scripts/fork/create.scm: New files.
* Makefile.am (MODULES): Add the new files.
* guix/build/utils.scm (invoke/stdout): New procedure.
* guix/utils.scm (chain-cut): New procedure.
* guix/scripts/git/authenticate.scm
(commit-short-id): Remove procedure, and use its existing duplicate in
guix/channels.scm.
(openpgp-fingerprint*, current-branch, show-stats): Move procedures to
the files below.
* guix/channels.scm (openpgp-fingerprint*): Moved here.
* guix/git.scm (repository-current-branch): Moved here and renamed from
'current-branch'.
* guix/git-authenticate.scm (show-authentication-stats): Moved here and
renamed from 'show-stats'.

Change-Id: I45ba37f434e136f6d496c741d9a933280f9ccf88
---
 Makefile.am                       |   2 +
 guix/build/utils.scm              |  20 +++
 guix/channels.scm                 |  13 ++
 guix/git-authenticate.scm         |  17 ++
 guix/git.scm                      |  10 ++
 guix/scripts/fork.scm             |  67 ++++++++
 guix/scripts/fork/create.scm      | 257 ++++++++++++++++++++++++++++++
 guix/scripts/git/authenticate.scm |  45 +-----
 guix/utils.scm                    |  33 ++++
 9 files changed, 423 insertions(+), 41 deletions(-)
 create mode 100644 guix/scripts/fork.scm
 create mode 100644 guix/scripts/fork/create.scm
  

Comments

Ludovic Courtès Feb. 14, 2025, 11:51 p.m. UTC | #1
Hello,

One quick comment…

45mg <45mg.writes@gmail.com> skribis:

> +      (info (G_ "Adding key to keyring branch...~%"))
> +      (invoke-git "switch" "keyring")
> +      (invoke "gpg"
> +              "--armor" "--export"
> +              "-o" (string-append directory "/" key-file-name)
> +              signing-key)
> +      (invoke-git "add" "--" key-file-name)
> +      (invoke-git "commit" "-m" "Add key for fork introduction.")
> +
> +      (info (G_ "Setting up fork branch...~%"))
> +      (invoke-git "switch" "--create" "fork" "master")
> +      (when channel-url
> +        (update-channel-url (string-append directory "/.guix-channel")
> +                            channel-url))
> +      (rewrite-authorizations (string-append directory "/.guix-authorizations")
> +                              introduction-name signing-key)
> +      (invoke-git "add" "--"
> +                  (string-append directory "/.guix-authorizations")
> +                  (string-append directory "/.guix-channel"))
> +      (invoke-git "commit"
> +                  (string-append "--gpg-sign=" signing-key)
> +                  "-m"
> +                  (string-append
> +                   "Initial fork commit.\n\n"
> +                   ".guix-authorizations: Allow only " introduction-name "'s key."
> +                   (if channel-url
> +                       "\n.guix-channels: Update channel URL."
> +                       "")))

Apologies for not following the initial discussions that led to this
design.  To make sure I understand, what this does is create
‘.guix-authorizations’ with a single key and then makes that commit the
introduction of the fork, right?

The idea being that one would keep rebasing their fork and ‘guix fork’
would take care of updating the introduction in ‘.git/config’ so you can
keep authenticating it, right?

This looks interesting and a much needed improvement.  There’s quite a
bit to discuss about the implementation; in particular, it would be cool
if we could avoid duplicating most of (guix scripts git authenticate)
and if we could avoid shelling out to various commands, as in the
snippet above, to the extent possible (for instance using Guile-Git).

Thanks for your work!

Ludo’.
  

Patch

diff --git a/Makefile.am b/Makefile.am
index f759803b8b..c628450a5a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -377,6 +377,8 @@  MODULES =					\
   guix/scripts/size.scm				\
   guix/scripts/git.scm				\
   guix/scripts/git/authenticate.scm		\
+  guix/scripts/fork.scm			\
+  guix/scripts/fork/create.scm			\
   guix/scripts/graph.scm			\
   guix/scripts/weather.scm			\
   guix/scripts/container.scm			\
diff --git a/guix/build/utils.scm b/guix/build/utils.scm
index 94714bf397..e8bd39f5de 100644
--- a/guix/build/utils.scm
+++ b/guix/build/utils.scm
@@ -10,6 +10,8 @@ 
 ;;; Copyright © 2021, 2022 Maxime Devos <maximedevos@telenet.be>
 ;;; Copyright © 2021 Brendan Tildesley <mail@brendan.scot>
 ;;; Copyright © 2023 Carlo Zancanaro <carlo@zancanaro.id.au>
+;;; Copyright © 2025 Tomas Volf <~@wolfsden.cz>
+;;; Copyright © 2025 45mg <45mg.writes@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -39,6 +41,7 @@  (define-module (guix build utils)
   #:use-module (ice-9 rdelim)
   #:use-module (ice-9 format)
   #:use-module (ice-9 threads)
+  #:use-module (ice-9 popen)
   #:use-module (rnrs bytevectors)
   #:use-module (rnrs io ports)
   #:re-export (alist-cons
@@ -128,6 +131,7 @@  (define-module (guix build utils)
             report-invoke-error
 
             invoke/quiet
+            invoke/stdout
 
             make-desktop-entry-file
 
@@ -889,6 +893,22 @@  (define (invoke/quiet program . args)
         (line
          (loop (cons line lines)))))))
 
+(define (invoke/stdout program . args)
+  "Invoke PROGRAM with ARGS and capture PROGRAM's standard output.  If PROGRAM
+succeeds, return its standard output as a string.  Otherwise, raise an
+'&invoke-error' condition."
+  (let* ((port (apply open-pipe* OPEN_READ program args))
+         (data (get-string-all port))
+         (code (close-pipe port)))
+    (unless (zero? code)
+      (raise (condition (&invoke-error
+                         (program program)
+                         (arguments args)
+                         (exit-status (status:exit-val code))
+                         (term-signal (status:term-sig code))
+                         (stop-signal (status:stop-sig code))))))
+    data))
+
 
 ;;;
 ;;; Text substitution (aka. sed).
diff --git a/guix/channels.scm b/guix/channels.scm
index 4700f7a45d..6ca8e64881 100644
--- a/guix/channels.scm
+++ b/guix/channels.scm
@@ -47,6 +47,7 @@  (define-module (guix channels)
   #:use-module (guix packages)
   #:use-module (guix progress)
   #:use-module (guix derivations)
+  #:autoload   (rnrs bytevectors) (bytevector-length)
   #:use-module (guix diagnostics)
   #:use-module (guix sets)
   #:use-module (guix store)
@@ -81,6 +82,7 @@  (define-module (guix channels)
 
             openpgp-fingerprint->bytevector
             openpgp-fingerprint
+            openpgp-fingerprint*
 
             %default-guix-channel
             %default-channels
@@ -171,6 +173,17 @@  (define-syntax openpgp-fingerprint
       ((_ str)
        #'(openpgp-fingerprint->bytevector str)))))
 
+(define (openpgp-fingerprint* str)
+  "Like openpgp-fingerprint, but with error handling from (guix diagnostics)."
+    (unless (string-every (char-set-union char-set:hex-digit
+                                          char-set:whitespace)
+                          str)
+      (leave (G_ "~a: invalid OpenPGP fingerprint~%") str))
+    (let ((fingerprint (openpgp-fingerprint str)))
+      (unless (= 20 (bytevector-length fingerprint))
+        (leave (G_ "~a: wrong length for OpenPGP fingerprint~%") str))
+      fingerprint))
+
 (define %guix-channel-introduction
   ;; Introduction of the official 'guix channel.  The chosen commit is the
   ;; first one that introduces '.guix-authorizations' on the 'staging'
diff --git a/guix/git-authenticate.scm b/guix/git-authenticate.scm
index 37c69d0880..8bc7fb6fb3 100644
--- a/guix/git-authenticate.scm
+++ b/guix/git-authenticate.scm
@@ -40,6 +40,7 @@  (define-module (guix git-authenticate)
   #:use-module (rnrs bytevectors)
   #:use-module (rnrs io ports)
   #:use-module (ice-9 match)
+  #:use-module (ice-9 format)
   #:autoload   (ice-9 pretty-print) (pretty-print)
   #:export (read-authorizations
             commit-signing-key
@@ -52,6 +53,7 @@  (define-module (guix git-authenticate)
 
             repository-cache-key
             authenticate-repository
+            show-authentication-stats
 
             git-authentication-error?
             git-authentication-error-commit
@@ -449,3 +451,18 @@  (define* (authenticate-repository repository start signer
                                       (oid->string (commit-id end-commit)))
 
           stats))))
+
+(define (show-authentication-stats stats)
+  "Display STATS, an alist containing commit signing stats as returned by
+'authenticate-repository'."
+  (format #t (G_ "Signing statistics:~%"))
+  (for-each (match-lambda
+              ((signer . count)
+               (format #t "  ~a ~10d~%"
+                       (openpgp-format-fingerprint
+                        (openpgp-public-key-fingerprint signer))
+                       count)))
+            (sort stats
+                  (match-lambda*
+                    (((_ . count1) (_ . count2))
+                     (> count1 count2))))))
diff --git a/guix/git.scm b/guix/git.scm
index 6ac6e4e3a2..afeacb53aa 100644
--- a/guix/git.scm
+++ b/guix/git.scm
@@ -59,6 +59,7 @@  (define-module (guix git)
             with-git-error-handling
             false-if-git-not-found
             repository-info
+            repository-current-branch
             update-cached-checkout
             url+commit->name
             latest-repository-commit
@@ -401,6 +402,15 @@  (define (repository-info directory)
     (lambda _
       (values #f #f #f))))
 
+(define (repository-current-branch repository)
+  "Return the name of the checked out branch of REPOSITORY or #f if it could
+not be determined."
+  (and (not (repository-head-detached? repository))
+       (let* ((head (repository-head repository))
+              (name (reference-name head)))
+         (and (string-prefix? "refs/heads/" name)
+              (string-drop name (string-length "refs/heads/"))))))
+
 (define* (update-submodules repository
                             #:key (log-port (current-error-port))
                             (fetch-options #f))
diff --git a/guix/scripts/fork.scm b/guix/scripts/fork.scm
new file mode 100644
index 0000000000..2d97bcb93f
--- /dev/null
+++ b/guix/scripts/fork.scm
@@ -0,0 +1,67 @@ 
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2025 45mg <45mg.writes@gmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix scripts fork)
+  #:use-module (ice-9 match)
+  #:use-module (guix ui)
+  #:use-module (guix scripts)
+  #:export (guix-fork))
+
+(define (show-help)
+  (display (G_ "Usage: guix fork ACTION ARGS...
+Create and manage authenticated forks of Guix.\n"))
+  (newline)
+  (display (G_ "The valid values for ACTION are:\n"))
+  (newline)
+  (display (G_ "\
+   create    set up a fork of Guix\n"))
+  (newline)
+  (display (G_ "
+  -h, --help             display this help and exit"))
+  (display (G_ "
+  -V, --version          display version information and exit"))
+  (newline)
+  (show-bug-report-information))
+
+(define %sub-commands '("create"))
+
+(define (resolve-sub-command name)
+  (let ((module (resolve-interface
+                 `(guix scripts fork ,(string->symbol name))))
+        (proc (string->symbol (string-append "guix-fork-" name))))
+    (module-ref module proc)))
+
+(define-command (guix-fork . args)
+  (category plumbing)
+  (synopsis "operate on Guix forks")
+
+  (with-error-handling
+    (match args
+      (()
+       (format (current-error-port)
+               (G_ "guix fork: missing sub-command~%")))
+      ((or ("-h") ("--help"))
+       (leave-on-EPIPE (show-help))
+       (exit 0))
+      ((or ("-V") ("--version"))
+       (show-version-and-exit "guix fork"))
+      ((sub-command args ...)
+       (if (member sub-command %sub-commands)
+           (apply (resolve-sub-command sub-command) args)
+           (format (current-error-port)
+                   (G_ "guix fork: invalid sub-command~%")))))))
diff --git a/guix/scripts/fork/create.scm b/guix/scripts/fork/create.scm
new file mode 100644
index 0000000000..8b5555947b
--- /dev/null
+++ b/guix/scripts/fork/create.scm
@@ -0,0 +1,257 @@ 
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2025 Tomas Volf <~@wolfsden.cz>
+;;; Copyright © 2025 45mg <45mg.writes@gmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix scripts fork create)
+  #:use-module (guix ui)
+  #:use-module (guix scripts)
+  #:use-module ((guix utils) #:select (chain-cut))
+  #:use-module (guix build utils)
+  #:use-module (guix channels)
+  #:use-module (ice-9 exceptions)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 popen)
+  #:use-module (ice-9 pretty-print)
+  #:use-module (ice-9 string-fun)
+  #:use-module (ice-9 textual-ports)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-13)
+  #:use-module (srfi srfi-26)
+  #:use-module (srfi srfi-37)
+  #:use-module (srfi srfi-71)
+  #:export (guix-fork-create))
+
+;;; Commentary:
+;;;
+;;; Create a fork of Guix, by running a series of git commands.
+;;;
+;;; Code:
+
+(define %options
+  ;; Specifications of the command-line options.
+  (list (option '(#\h "help") #f #f
+                (lambda args
+                  (show-help)
+                  (exit 0)))
+        (option '(#\V "version") #f #f
+                (lambda args
+                  (show-version-and-exit "guix fork create")))
+        (option '("upstream") #t #f
+                (lambda (opt name arg result)
+                  (alist-cons 'upstream arg result)))
+        (option '("channel-url") #t #f
+                (lambda (opt name arg result)
+                  (alist-cons 'channel-url arg result)))
+        (option '("use-existing") #f #f
+                (lambda (opt name arg result)
+                  (alist-cons 'use-existing? #t result)))
+        (option '("git-parameter") #t #f
+                (lambda (opt name arg result)
+                  (let ((git-parameters (assoc-ref result 'git-parameters)))
+                    (if git-parameters
+                        (alist-cons 'git-parameters (cons arg git-parameters) result)
+                        (alist-cons 'git-parameters (list arg) result)))))))
+
+(define %default-options
+  `((upstream . ,(channel-url %default-guix-channel))))
+
+(define %usage
+  (format #f (G_ "Usage: guix fork create SIGNING_KEY [DIRECTORY OPTIONS...]
+Create a fork of Guix in DIRECTORY, using SIGNING_KEY to sign the introductory
+commit.
+DIRECTORY defaults to ./guix.
+
+      --upstream=URI     the repository to clone from
+                         (defaults to ~a)
+      --channel-url=URI  optional URI, used to replace the channel URL
+                         and the existing 'origin' remote (which is
+                         renamed to 'upstream')
+      --use-existing     Use existing clone of Guix in DIRECTORY
+      --git-parameter PARAMETER
+                         Specify configuration PARAMETER for git, via
+                         '-c' option (can pass multiple times)
+
+  -h, --help             display this help and exit
+  -V, --version          display version information and exit
+")
+      (channel-url %default-guix-channel)))
+
+(define (show-help)
+  (display %usage)
+  (newline)
+  (show-bug-report-information))
+
+(define (missing-arguments)
+    (leave (G_ "wrong number of arguments; \
+required SIGNING_KEY~%")))
+
+
+;;;
+;;; Helper prodecures.
+;;;
+
+(define (fingerprint->key-file-name fingerprint)
+  (let* ((listing (invoke/stdout "gpg" "--list-key" "--with-colons" fingerprint))
+         (uid (chain-cut listing
+                           (string-split <> #\newline)
+                           (filter (cut string-prefix? "uid:" <>) <>)
+                           first
+                           (string-split <> #\:)
+                           tenth))
+         (email-name (string-delete
+                      (cut eq? <> #\.)
+                      (substring uid
+                                 (1+ (or (string-index-right uid #\<)
+                                         -1))  ;no name in uid
+                                 (string-index uid #\@))))
+         (key-id (chain-cut listing
+                      (string-split <> #\newline)
+                      (filter (cut string-prefix? "pub:" <>) <>)
+                      car
+                      (string-split <> #\:)
+                      fifth
+                      (string-take-right <> 8))))
+    (string-append email-name "-" key-id ".key")))
+
+(define (update-channel-url file channel-url)
+  "Modify .guix_channel FILE.
+Change the channel url to CHANNEL-URL."
+  (let ((channel-data (call-with-input-file file read)))
+    (assq-set! (cdr channel-data) 'url (list channel-url))
+    (call-with-output-file file
+      (lambda (file)
+        (display ";; This is a Guix channel.\n\n" file)
+        (pretty-print channel-data file)))))
+
+(define (rewrite-authorizations file name fingerprint)
+  "Rewrite .guix-authorizations FILE to contain a single authorization
+consisting of NAME and FINGERPRINT."
+  (let ((auth-data (call-with-input-file file read)))
+    (list-set! auth-data (1- (length auth-data))
+               `((,fingerprint (name ,name))))
+    (call-with-output-file file
+      (lambda (file)
+        (display ";; This file, which is best viewed as -*- Scheme -*-, lists the OpenPGP keys
+;; currently authorized to sign commits in this fork branch.
+
+" file)
+        (pretty-print auth-data file)))))
+
+
+;;;
+;;; Entry point.
+;;;
+
+(define (guix-fork-create . args)
+  (define options
+    (parse-command-line args %options (list %default-options)
+                        #:build-options? #f))
+
+  (define (command-line-arguments lst)
+    (reverse (filter-map (match-lambda
+                           (('argument . arg) arg)
+                           (_ #f))
+                         lst)))
+
+  (with-error-handling
+    (let* ((signing-key directory (match (command-line-arguments options)
+                                    ((signing-key directory)
+                                     (values signing-key directory))
+                                    ((signing-key)
+                                     (values signing-key "guix"))
+                                    (_ (missing-arguments))))
+           (upstream (assoc-ref options 'upstream))
+           (channel-url (assoc-ref options 'channel-url))
+           (use-existing? (assoc-ref options 'use-existing?))
+           (git-parameters (assoc-ref options 'git-parameters))
+           (git-c-options  ;'("-c" "param1" "-c" "param2" ...)
+            (let loop ((opts '()) (params git-parameters))
+              (if (or (not params) (null-list? params))
+                  opts
+                  (loop (append
+                         opts (list "-c" (first params)))
+                        (drop params 1)))))
+
+           (key-file-name (fingerprint->key-file-name signing-key))
+           (introduction-name (car (string-split key-file-name #\-)))
+
+           (upstream-branch-name "master"))
+
+      (define (invoke-git . args)
+        (apply invoke `("git" ,@git-c-options "-C" ,directory ,@args)))
+
+      (unless use-existing?
+        (info (G_ "Cloning from upstream ~a...~%") upstream)
+        (invoke "git" "clone" upstream directory))
+
+      (info (G_ "Authenticating upstream commits...~%"))
+
+      (when channel-url
+        (info (G_ "Renaming existing 'origin' remote to 'upstream'...~%"))
+        (invoke-git "remote" "rename" "origin" "upstream")
+        (info (G_ "Using provided channel URL for new 'origin' remote...~%"))
+        (invoke-git "remote" "add" "origin" channel-url))
+
+      (set! upstream-branch-name
+            (chain-cut
+             (invoke/stdout "git"
+                            "-C" directory
+                            "symbolic-ref"
+                            (string-append "refs/remotes/"
+                                           (if channel-url "upstream" "origin")
+                                           "/HEAD"))
+             string-trim-right
+             (string-split <> #\/)
+             last))
+
+      (info (G_ "Adding key to keyring branch...~%"))
+      (invoke-git "switch" "keyring")
+      (invoke "gpg"
+              "--armor" "--export"
+              "-o" (string-append directory "/" key-file-name)
+              signing-key)
+      (invoke-git "add" "--" key-file-name)
+      (invoke-git "commit" "-m" "Add key for fork introduction.")
+
+      (info (G_ "Setting up fork branch...~%"))
+      (invoke-git "switch" "--create" "fork" "master")
+      (when channel-url
+        (update-channel-url (string-append directory "/.guix-channel")
+                            channel-url))
+      (rewrite-authorizations (string-append directory "/.guix-authorizations")
+                              introduction-name signing-key)
+      (invoke-git "add" "--"
+                  (string-append directory "/.guix-authorizations")
+                  (string-append directory "/.guix-channel"))
+      (invoke-git "commit"
+                  (string-append "--gpg-sign=" signing-key)
+                  "-m"
+                  (string-append
+                   "Initial fork commit.\n\n"
+                   ".guix-authorizations: Allow only " introduction-name "'s key."
+                   (if channel-url
+                       "\n.guix-channels: Update channel URL."
+                       "")))
+
+      (info (G_ "Successfully created Guix fork in ~a.
+You should run the following command next:
+guix fork authenticate ~a ~a ~a~%")
+            directory
+            upstream-branch-name
+            (string-trim-right (invoke/stdout "git" "-C" directory "rev-parse" "HEAD"))
+            signing-key))))
diff --git a/guix/scripts/git/authenticate.scm b/guix/scripts/git/authenticate.scm
index e3ecb67c89..154aae9b14 100644
--- a/guix/scripts/git/authenticate.scm
+++ b/guix/scripts/git/authenticate.scm
@@ -23,8 +23,8 @@  (define-module (guix scripts git authenticate)
   #:use-module (guix git-authenticate)
   #:autoload   (guix openpgp) (openpgp-format-fingerprint
                                openpgp-public-key-fingerprint)
-  #:use-module ((guix channels) #:select (openpgp-fingerprint))
-  #:use-module ((guix git) #:select (with-git-error-handling))
+  #:use-module ((guix channels) #:select (openpgp-fingerprint*))
+  #:use-module ((guix git) #:select (with-git-error-handling commit-short-id repository-current-branch))
   #:use-module (guix progress)
   #:use-module (guix base64)
   #:autoload   (rnrs bytevectors) (bytevector-length)
@@ -76,15 +76,6 @@  (define %options
 (define %default-options
   '())
 
-(define (current-branch repository)
-  "Return the name of the checked out branch of REPOSITORY or #f if it could
-not be determined."
-  (and (not (repository-head-detached? repository))
-       (let* ((head (repository-head repository))
-              (name (reference-name head)))
-         (and (string-prefix? "refs/heads/" name)
-              (string-drop name (string-length "refs/heads/"))))))
-
 (define (config-value repository key)
   "Return the config value associated with KEY in the 'guix.authentication' or
 'guix.authentication-BRANCH' name space in REPOSITORY, or #f if no such config
@@ -94,7 +85,7 @@  (define (config-value repository key)
                   ((_ exp)
                    (catch 'git-error (lambda () exp) (const #f))))))
     (let* ((config (repository-config repository))
-           (branch (current-branch repository)))
+           (branch (repository-current-branch repository)))
       ;; First try the BRANCH-specific value, then the generic one.`
       (or (and branch
                (false-if-git-error
@@ -194,21 +185,6 @@  (define (install-hooks repository)
       (warning (G_ "cannot determine where to install hooks\
  (Guile-Git too old?)~%"))))
 
-(define (show-stats stats)
-  "Display STATS, an alist containing commit signing stats as returned by
-'authenticate-repository'."
-  (format #t (G_ "Signing statistics:~%"))
-  (for-each (match-lambda
-              ((signer . count)
-               (format #t "  ~a ~10d~%"
-                       (openpgp-format-fingerprint
-                        (openpgp-public-key-fingerprint signer))
-                       count)))
-            (sort stats
-                  (match-lambda*
-                    (((_ . count1) (_ . count2))
-                     (> count1 count2))))))
-
 (define (show-help)
   (display (G_ "Usage: guix git authenticate COMMIT SIGNER [OPTIONS...]
 Authenticate the given Git checkout using COMMIT/SIGNER as its introduction.\n"))
@@ -251,19 +227,6 @@  (define (guix-git-authenticate . args)
                            (_ #f))
                          lst)))
 
-  (define commit-short-id
-    (compose (cut string-take <> 7) oid->string commit-id))
-
-  (define (openpgp-fingerprint* str)
-    (unless (string-every (char-set-union char-set:hex-digit
-                                          char-set:whitespace)
-                          str)
-      (leave (G_ "~a: invalid OpenPGP fingerprint~%") str))
-    (let ((fingerprint (openpgp-fingerprint str)))
-      (unless (= 20 (bytevector-length fingerprint))
-        (leave (G_ "~a: wrong length for OpenPGP fingerprint~%") str))
-      fingerprint))
-
   (define (make-reporter start-commit end-commit commits)
     (format (current-error-port)
             (G_ "Authenticating commits ~a to ~a (~h new \
@@ -321,7 +284,7 @@  (define (guix-git-authenticate . args)
          (install-hooks repository))
 
        (when (and show-stats? (not (null? stats)))
-         (show-stats stats))
+         (show-authentication-stats stats))
 
        (info (G_ "successfully authenticated commit ~a~%")
              (oid->string end))))))
diff --git a/guix/utils.scm b/guix/utils.scm
index b6cf5aea4f..e07e89c321 100644
--- a/guix/utils.scm
+++ b/guix/utils.scm
@@ -21,6 +21,8 @@ 
 ;;; Copyright © 2023 Zheng Junjie <873216071@qq.com>
 ;;; Copyright © 2023 Foundation Devices, Inc. <hello@foundationdevices.com>
 ;;; Copyright © 2024 Herman Rimm <herman@rimm.ee>
+;;; Copyright © 2025 Tomas Volf <~@wolfsden.cz>
+;;; Copyright © 2025 45mg <45mg.writes@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -163,6 +165,8 @@  (define-module (guix utils)
             call-with-compressed-output-port
             canonical-newline-port
 
+            chain-cut
+
             string-distance
             string-closest
 
@@ -1193,6 +1197,35 @@  (define-syntax current-source-directory
           ;; raising an error would upset Geiser users
           #f))))))
 
+
+;;;
+;;; Higher-order functions.
+;;;
+
+(define-syntax chain-cut
+  (lambda (x)
+    "Apply each successive form to the result of evaluating the previous one.
+Before applying, expand each form (op ...) to (cut op ...).
+
+Examples:
+
+    (chain-cut '(1 2 3) cdr car)
+ => (car (cdr '(1 2 3)))
+
+    (chain-cut 2 (- 3 <>) 1+)
+ => (1+ ((cut - 3 <>) 2))
+ => (1+ (- 3 2))
+"
+    (syntax-case x ()
+      ((chain-cut init op) (identifier? #'op)
+       #'(op init))
+      ((chain-cut init (op ...))
+       #'((cut op ...) init))
+      ((chain-cut init op op* ...) (identifier? #'op)
+       #'(chain-cut (op init) op* ...))
+      ((chain-cut init (op ...) op* ...)
+       #'(chain-cut ((cut op ...) init) op* ...)))))
+
 
 ;;;
 ;;; String comparison.