code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 tests)
  #:use-module ((guix config) #:select (%storedir %localstatedir))
  #:use-module (guix store)
  #:use-module (guix derivations)
  #:use-module (guix packages)
  #:use-module (guix base32)
  #:use-module (guix serialization)
  #:use-module (guix monads)
  #:use-module ((guix utils) #:select (substitute-keyword-arguments))
  #:use-module ((guix build utils) #:select (mkdir-p))
  #:use-module ((gcrypt hash) #:hide (sha256))
  #:use-module (guix build-system gnu)
  #:use-module (gnu packages base)
  #:use-module (gnu packages bootstrap)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-64)
  #:use-module (rnrs bytevectors)
  #:use-module (ice-9 match)
  #:use-module (ice-9 binary-ports)
  #:use-module (web uri)
  #:export (open-connection-for-tests
            with-external-store
            %seed
            random-text
            random-bytevector
            file=?
            canonical-file?
            network-reachable?
            shebang-too-long?
            with-environment-variable

            search-bootstrap-binary

            mock
            %test-substitute-urls
            test-assertm
            test-equalm
            %substitute-directory
            with-derivation-narinfo
            with-derivation-substitute
            dummy-package
            dummy-origin

            gnu-make-for-tests))

;;; Commentary:
;;;
;;; This module provide shared infrastructure for the test suite.  For
;;; internal use only.
;;;
;;; Code:

(define %test-substitute-urls
  ;; URLs where to look for substitutes during tests.
  (make-parameter
   (or (and=> (getenv "GUIX_BINARY_SUBSTITUTE_URL") list)
       '())))

(define* (open-connection-for-tests #:optional (uri (%daemon-socket-uri)))
  "Open a connection to the build daemon for tests purposes and return it."
  (guard (c ((store-error? c)
             (format (current-error-port)
                     "warning: build daemon error: ~s~%" c)
             #f))
    (let ((store (open-connection uri)))
      ;; Make sure we build everything by ourselves.
      (set-build-options store
                         #:use-substitutes? #f
                         #:substitute-urls (%test-substitute-urls))

      ;; Use the bootstrap Guile when running tests, so we don't end up
      ;; building everything in the temporary test store.
      (%guile-for-build (package-derivation store %bootstrap-guile))

      store)))

(define (bootstrap-binary-file program system)
  "Return the absolute file name where bootstrap binary PROGRAM for SYSTEM is
stored."
  (string-append (dirname (search-path %load-path
                                       "gnu/packages/bootstrap.scm"))
                 "/bootstrap/" system "/" program))

(define (search-bootstrap-binary file-name system)
  "Search the bootstrap binary FILE-NAME for SYSTEM.  Raise an error if not
found."
  ;; Note: Keep bootstrap binaries on the local file system so that the 'guix'
  ;; package can provide them as inputs and copy them to the right place.
  (let* ((system (match system
                   ("x86_64-linux" "i686-linux")
                   (_ system)))
         (file   (bootstrap-binary-file file-name system)))
    (if (file-exists? file)
        file
        (with-store store
          (run-with-store store
            (mlet %store-monad ((drv (origin->derivation
                                      (bootstrap-executable file-name system))))
              (mbegin %store-monad
                (built-derivations (list drv))
                (begin
                  (mkdir-p (dirname file))
                  (copy-file (derivation->output-path drv) file)
                  (return file)))))))))

(define (call-with-external-store proc)
  "Call PROC with an open connection to the external store or #f it there is
no external store to talk to."
  (parameterize ((%daemon-socket-uri
                  (string-append %localstatedir
                                 "/guix/daemon-socket/socket"))
                 (%store-prefix %storedir))
    (define store
      (catch #t
        (lambda ()
          (open-connection))
        (const #f)))

    (dynamic-wind
      (const #t)
      (lambda ()
        ;; Since we're using a different store we must clear the
        ;; package-derivation cache.
        (hash-clear! (@@ (guix packages) %derivation-cache))

        (proc store))
      (lambda ()
        (when store
          (close-connection store))))))

(define-syntax-rule (with-external-store store exp ...)
  "Evaluate EXP with STORE bound to the external store rather than the
temporary test store, or #f if there is no external store to talk to.

This is meant to be used for tests that need to build packages that would be
too expensive to build entirely in the test store."
  (call-with-external-store (lambda (store) exp ...)))

(define (random-seed)
  (or (and=> (getenv "GUIX_TESTS_RANDOM_SEED")
             number->string)
      (logxor (getpid) (car (gettimeofday)))))

(define (%seed)
  (let ((seed (random-seed)))
    (format (current-error-port) "random seed for tests: ~a~%"
            seed)
    (let ((result (seed->random-state seed)))
      (set! %seed (lambda () result))
      result)))

(define (random-text)
  "Return the hexadecimal representation of a random number."
  (number->string (random (expt 2 256) (%seed)) 16))

(define (random-bytevector n)
  "Return a random bytevector of N bytes."
  (let ((bv (make-bytevector n)))
    (let loop ((i 0))
      (if (< i n)
          (begin
            (bytevector-u8-set! bv i (random 256 (%seed)))
            (loop (1+ i)))
          bv))))

(define (file=? a b)
  "Return true if files A and B have the same type and same content."
  (and (eq? (stat:type (lstat a)) (stat:type (lstat b)))
       (case (stat:type (lstat a))
         ((regular)
          (equal?
           (call-with-input-file a get-bytevector-all)
           (call-with-input-file b get-bytevector-all)))
         ((symlink)
          (string=? (readlink a) (readlink b)))
         (else
          (error "what?" (lstat a))))))

(define (canonical-file? file)
  "Return #t if FILE is in the store, is read-only, and its mtime is 1."
  (let ((st (lstat file)))
    (or (not (string-prefix? (%store-prefix) file))
        (eq? 'symlink (stat:type st))
        (and (= 1 (stat:mtime st))
             (zero? (logand #o222 (stat:mode st)))))))

(define (network-reachable?)
  "Return true if we can reach the Internet."
  (false-if-exception (getaddrinfo "www.gnu.org" "80" AI_NUMERICSERV)))

(define-syntax-rule (mock (module proc replacement) body ...)
  "Within BODY, replace the definition of PROC from MODULE with the definition
given by REPLACEMENT."
  (let* ((m (resolve-module 'module))
         (original (module-ref m 'proc)))
    (dynamic-wind
      (lambda () (module-set! m 'proc replacement))
      (lambda () body ...)
      (lambda () (module-set! m 'proc original)))))

(define-syntax-rule (test-assertm name exp)
  "Like 'test-assert', but EXP is a monadic value.  A new connection to the
store is opened."
  (test-assert name
    (let ((store (open-connection-for-tests)))
      (dynamic-wind
        (const #t)
        (lambda ()
          (run-with-store store exp
                          #:guile-for-build (%guile-for-build)))
        (lambda ()
          (close-connection store))))))

(define-syntax-rule (test-equalm name value exp)
  "Like 'test-equal', but EXP is a monadic value.  A new connection to the
store is opened."
  (test-equal name
    value
    (with-store store
      (run-with-store store exp
                      #:guile-for-build (%guile-for-build)))))

(define-syntax-rule (with-environment-variable variable value body ...)
  "Run BODY with VARIABLE set to VALUE."
  (let ((orig (getenv variable)))
    (dynamic-wind
      (lambda ()
        (setenv variable value))
      (lambda ()
        body ...)
      (lambda ()
        (if orig
            (setenv variable orig)
            (unsetenv variable))))))

;;;
;;; Narinfo files, as used by the substituter.
;;;

(define* (derivation-narinfo drv #:key (nar "example.nar")
                             (sha256 (make-bytevector 32 0))
                             (references '()))
  "Return the contents of the narinfo corresponding to DRV, with the specified
REFERENCES (a list of store items); NAR should be the file name of the archive
containing the substitute for DRV, and SHA256 is the expected hash."
  (format #f "StorePath: ~a
URL: ~a
Compression: none
NarSize: 1234
NarHash: sha256:~a
References: ~a
System: ~a
Deriver: ~a~%"
          (derivation->output-path drv)       ; StorePath
          nar                                 ; URL
          (bytevector->nix-base32-string sha256)  ; NarHash
          (string-join (map basename references)) ; References
          (derivation-system drv)             ; System
          (basename
           (derivation-file-name drv))))      ; Deriver

(define %substitute-directory
  (make-parameter
   (and=> (getenv "GUIX_BINARY_SUBSTITUTE_URL")
          (compose uri-path string->uri))))

(define* (call-with-derivation-narinfo drv thunk
                                       #:key
                                       (sha256 (make-bytevector 32 0))
                                       (references '()))
  "Call THUNK in a context where fake substituter data, as read by 'guix
substitute', has been installed for DRV.  SHA256 is the hash of the
expected output of DRV."
  (let* ((output  (derivation->output-path drv))
         (dir     (%substitute-directory))
         (info    (string-append dir "/nix-cache-info"))
         (narinfo (string-append dir "/" (store-path-hash-part output)
                                 ".narinfo")))
    (dynamic-wind
      (lambda ()
        (call-with-output-file info
          (lambda (p)
            (format p "StoreDir: ~a\nWantMassQuery: 0\n"
                    (%store-prefix))))
        (call-with-output-file narinfo
          (lambda (p)
            (display (derivation-narinfo drv #:sha256 sha256
                                         #:references references)
                     p))))
      thunk
      (lambda ()
        (delete-file narinfo)
        (delete-file info)))))

(define-syntax with-derivation-narinfo
  (syntax-rules (sha256 references =>)
    "Evaluate BODY in a context where DRV looks substitutable from the
substituter's viewpoint."
    ((_ drv (sha256 => hash) (references => refs) body ...)
     (call-with-derivation-narinfo drv
       (lambda () body ...)
       #:sha256 hash
       #:references refs))
    ((_ drv (sha256 => hash) body ...)
     (with-derivation-narinfo drv
       (sha256 => hash) (references => '())
       body ...))
    ((_ drv body ...)
     (call-with-derivation-narinfo drv
       (lambda ()
         body ...)))))

(define* (call-with-derivation-substitute drv contents thunk
                                          #:key
                                          sha256
                                          (references '()))
  "Call THUNK in a context where a substitute for DRV has been installed,
using CONTENTS, a string, as its contents.  If SHA256 is true, use it as the
expected hash of the substitute; otherwise use the hash of the nar containing
CONTENTS."
  (define dir (%substitute-directory))
  (dynamic-wind
    (lambda ()
      (call-with-output-file (string-append dir "/example.out")
        (lambda (port)
          (display contents port)))
      (call-with-output-file (string-append dir "/example.nar")
        (lambda (p)
          (write-file (string-append dir "/example.out") p))))
    (lambda ()
      (let ((hash (call-with-input-file (string-append dir "/example.nar")
                    port-sha256)))
        ;; Create fake substituter data, to be read by 'guix substitute'.
        (call-with-derivation-narinfo drv
          thunk
          #:sha256 (or sha256 hash)
          #:references references)))
    (lambda ()
      (delete-file (string-append dir "/example.out"))
      (delete-file (string-append dir "/example.nar")))))

(define (shebang-too-long?)
  "Return true if the typical shebang in the current store would exceed
Linux's static limit---the BINPRM_BUF_SIZE constant, normally 128 characters
all included."
  (define shebang
    (string-append "#!" (%store-prefix) "/"
                   (make-string 32 #\a)
                   "-bootstrap-binaries-0/bin/bash\0"))

  (> (string-length shebang) 128))

(define-syntax with-derivation-substitute
  (syntax-rules (sha256 references =>)
    "Evaluate BODY in a context where DRV is substitutable with the given
CONTENTS."
    ((_ drv contents (sha256 => hash) (references => refs) body ...)
     (call-with-derivation-substitute drv contents
       (lambda () body ...)
       #:sha256 hash
       #:references refs))
    ((_ drv contents (sha256 => hash) body ...)
     (with-derivation-substitute drv contents
       (sha256 => hash) (references => '())
       body ...))
    ((_ drv contents body ...)
     (call-with-derivation-substitute drv contents
       (lambda ()
         body ...)))))

(define-syntax-rule (dummy-package name* extra-fields ...)
  "Return a \"dummy\" package called NAME*, with all its compulsory fields
initialized with default values, and with EXTRA-FIELDS set as specified."
  (let ((p (package
             (name name*) (version "0") (source #f)
             (build-system gnu-build-system)
             (synopsis #f) (description #f)
             (home-page #f) (license #f))))
    (package (inherit p) extra-fields ...)))

(define-syntax-rule (dummy-origin extra-fields ...)
  "Return a \"dummy\" origin, with all its compulsory fields initialized with
default values, and with EXTRA-FIELDS set as specified."
  (let ((o (origin (method #f) (uri "http://www.example.com")
                   (sha256 (base32 (make-string 52 #\x))))))
    (origin (inherit o) extra-fields ...)))

(define gnu-make-for-tests
  ;; This is a variant of 'gnu-make-boot0' that can be built with minimal
  ;; resources.
  (package-with-bootstrap-guile
   (package
     (inherit gnu-make)
     (name "make-test-boot0")
     (arguments
      `(#:guile ,%bootstrap-guile
        #:implicit-inputs? #f
        #:tests? #f                               ;cannot run "make check"
        ,@(substitute-keyword-arguments (package-arguments gnu-make)
            ((#:configure-flags flags ''())
             ;; As in 'gnu-make-boot0', work around a 'config.status' defect.
             `(cons "--disable-dependency-tracking" ,flags))
            ((#:phases phases)
             `(modify-phases ,phases
                (replace 'build
                  (lambda _
                    (invoke "./build.sh")
                    #t))
                (replace 'install
                  (lambda* (#:key outputs #:allow-other-keys)
                    (let* ((out (assoc-ref outputs "out"))
                           (bin (string-append out "/bin")))
                      (install-file "make" bin)
                      #t))))))))
     (native-inputs '())                          ;no need for 'pkg-config'
     (inputs %bootstrap-inputs-for-tests))))

;; Local Variables:
;; eval: (put 'call-with-derivation-narinfo 'scheme-indent-function 1)
;; eval: (put 'call-with-derivation-substitute 'scheme-indent-function 2)
;; End:

;;; tests.scm ends here


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 tests git)
  #:use-module (git)
  #:use-module ((guix git) #:select (with-repository))
  #:use-module (guix utils)
  #:use-module (guix build utils)
  #:use-module (ice-9 match)
  #:use-module (ice-9 control)
  #:export (git-command
            with-temporary-git-repository
            find-commit))

(define git-command
  (make-parameter "git"))

(define (populate-git-repository directory directives)
  "Initialize a new Git checkout and repository in DIRECTORY and apply
DIRECTIVES.  Each element of DIRECTIVES is an sexp like:

  (add \"foo.txt\" \"hi!\")

Return DIRECTORY on success."

  ;; Note: As of version 0.2.0, Guile-Git lacks the necessary bindings to do
  ;; all this, so resort to the "git" command.
  (define (git command . args)
    ;; Make sure Git doesn't rely on the user's config.
    (call-with-temporary-directory
     (lambda (home)
       (call-with-output-file (string-append home "/.gitconfig")
         (lambda (port)
           (display "[user]
  email = charlie@example.org\n  name = Charlie Guix\n"
                    port)))

       (with-environment-variables
        `(("GIT_CONFIG_NOSYSTEM" "1")
          ("GIT_ATTR_NOSYSTEM" "1")
          ("HOME" ,home))
        (apply invoke (git-command) "-C" directory
               command args)))))

  (mkdir-p directory)
  (git "init")

  (let loop ((directives directives))
    (match directives
      (()
       directory)
      ((('add file contents) rest ...)
       (let ((file (string-append directory "/" file)))
         (mkdir-p (dirname file))
         (call-with-output-file file
           (lambda (port)
             (display (if (string? contents)
                          contents
                          (with-repository directory repository
                            (contents repository)))
                      port)))
         (git "add" file)
         (loop rest)))
      ((('remove file) rest ...)
       (git "rm" "-f" file)
       (loop rest))
      ((('commit text) rest ...)
       (git "commit" "-m" text)
       (loop rest))
      ((('commit text ('signer fingerprint)) rest ...)
       (git "commit" "-m" text (string-append "--gpg-sign=" fingerprint))
       (loop rest))
      ((('tag name) rest ...)
       (git "tag" name)
       (loop rest))
      ((('branch name) rest ...)
       (git "branch" name)
       (loop rest))
      ((('checkout branch) rest ...)
       (git "checkout" branch)
       (loop rest))
      ((('merge branch message) rest ...)
       (git "merge" branch "-m" message)
       (loop rest))
      ((('merge branch message ('signer fingerprint)) rest ...)
       (git "merge" branch "-m" message
            (string-append "--gpg-sign=" fingerprint))
       (loop rest)))))

(define (call-with-temporary-git-repository directives proc)
  (call-with-temporary-directory
   (lambda (directory)
     (populate-git-repository directory directives)
     (proc directory))))

(define-syntax-rule (with-temporary-git-repository directory
                                                   directives exp ...)
  "Evaluate EXP in a context where DIRECTORY contains a checkout populated as
per DIRECTIVES."
  (call-with-temporary-git-repository directives
                                      (lambda (directory)
                                        exp ...)))

(define (find-commit repository message)
  "Return the commit in REPOSITORY whose message includes MESSAGE, a string."
  (let/ec return
    (fold-commits (lambda (commit _)
                    (and (string-contains (commit-message commit)
                                          message)
                         (return commit)))
                  #f
                  repository)
    (error "commit not found" message)))

repo_name: maximed/guix

license: mit


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 tests gnupg)
  #:use-module (guix openpgp)
  #:use-module (guix utils)
  #:use-module (guix build utils)
  #:use-module (rnrs io ports)
  #:use-module (ice-9 match)
  #:export (gpg-command
            gpgconf-command
            with-fresh-gnupg-setup

            %ed25519-public-key-file
            %ed25519-secret-key-file
            %ed25519bis-public-key-file
            %ed25519bis-secret-key-file

            read-openpgp-packet
            key-fingerprint
            key-id))

(define gpg-command
  (make-parameter "gpg"))

(define gpgconf-command
  (make-parameter "gpgconf"))

(define (call-with-fresh-gnupg-setup imported thunk)
  (call-with-temporary-directory
   (lambda (home)
     (with-environment-variables `(("GNUPGHOME" ,home))
       (dynamic-wind
         (lambda ()
           (for-each (lambda (file)
                       (invoke (gpg-command) "--import" file))
                     imported))
         thunk
         (lambda ()
           ;; Terminate 'gpg-agent' & co.
           (invoke (gpgconf-command) "--kill" "all")))))))

(define-syntax-rule (with-fresh-gnupg-setup imported exp ...)
  "Evaluate EXP in the context of a fresh GnuPG setup where all the files
listed in IMPORTED, and only them, have been imported.  This sets 'GNUPGHOME'
such that the user's real GnuPG files are left untouched.  The 'gpg-agent'
process is terminated afterwards."
  (call-with-fresh-gnupg-setup imported (lambda () exp ...)))

(define %ed25519-public-key-file
  (search-path %load-path "tests/ed25519.key"))
(define %ed25519-secret-key-file
  (search-path %load-path "tests/ed25519.sec"))
(define %ed25519bis-public-key-file
  (search-path %load-path "tests/ed25519bis.key"))
(define %ed25519bis-secret-key-file
  (search-path %load-path "tests/ed25519bis.sec"))

(define (read-openpgp-packet file)
  (get-openpgp-packet
   (open-bytevector-input-port
    (call-with-input-file file read-radix-64))))

(define key-fingerprint
  (compose openpgp-format-fingerprint
           openpgp-public-key-fingerprint
           read-openpgp-packet))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015, 2016, 2017, 2019 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
;;;
;;; 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 tests http)
  #:use-module (ice-9 threads)
  #:use-module (web server)
  #:use-module (web server http)
  #:use-module (web response)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-39)
  #:use-module (ice-9 match)
  #:export (with-http-server
            call-with-http-server
            %http-server-port
            %local-url))

;;; Commentary:
;;;
;;; Code to spawn a Web server for testing purposes.
;;;
;;; Code:

(define %http-server-port
  ;; TCP port to use for the stub HTTP server.
  ;; If 0, the OS will automatically choose
  ;; a port.
  (make-parameter 0))

(define (open-http-server-socket)
  "Return a listening socket for the web server and the port
actually listened at (in case %http-server-port was 0)."
  (catch 'system-error
    (lambda ()
      (let ((sock (socket PF_INET SOCK_STREAM 0)))
        (setsockopt sock SOL_SOCKET SO_REUSEADDR 1)
        (bind sock
              (make-socket-address AF_INET INADDR_LOOPBACK
                                   (%http-server-port)))
        (values sock
                (sockaddr:port (getsockname sock)))))
    (lambda args
      (let ((err (system-error-errno args)))
        (format (current-error-port)
                "warning: cannot run Web server for tests: ~a~%"
                (strerror err))
        (values #f #f)))))

(define* (%local-url #:optional (port (%http-server-port)))
  (when (= port 0)
    (error "no web server is running!"))
  ;; URL to use for 'home-page' tests.
  (string-append "http://localhost:" (number->string port)
                 "/foo/bar"))

(define* (call-with-http-server responses+data thunk)
  "Call THUNK with an HTTP server running and returning RESPONSES+DATA on HTTP
requests.  Each element of RESPONSES+DATA must be a tuple containing a
response and a string, or an HTTP response code and a string.

%http-server-port will be set to the port listened at
The port listened at will be set for the dynamic extent of THUNK."
  (define responses
    (map (match-lambda
           (((? response? response) data)
            (list response data))
           (((? integer? code) data)
            (list (build-response #:code code
                                  #:reason-phrase "Such is life")
                  data)))
         responses+data))

  (define (http-write server client response body)
    "Write RESPONSE."
    (let* ((response (write-response response client))
           (port     (response-port response)))
      (cond
       ((not body))                               ;pass
       (else
        (write-response-body response body)))
      (close-port port)
      (when (null? responses)
        (quit #t))                                ;exit the server thread
      (values)))

  ;; Mutex and condition variable to synchronize with the HTTP server.
  (define %http-server-lock (make-mutex))
  (define %http-server-ready (make-condition-variable))
  (define %http-real-server-port #f)

  (define (http-open . args)
    "Start listening for HTTP requests and signal %HTTP-SERVER-READY."
    (with-mutex %http-server-lock
      (let ((result (apply (@@ (web server http) http-open) args)))
        (signal-condition-variable %http-server-ready)
        result)))

  (define-server-impl stub-http-server
    ;; Stripped-down version of Guile's built-in HTTP server.
    http-open
    (@@ (web server http) http-read)
    http-write
    (@@ (web server http) http-close))

  (define (server-body)
    (define (handle request body)
      (match responses
        (((response data) rest ...)
         (set! responses rest)
         (values response data))))

    (let-values (((socket port) (open-http-server-socket)))
      (set! %http-real-server-port port)
      (catch 'quit
        (lambda ()
          (run-server handle stub-http-server
                      `(#:socket ,socket)))
        (lambda _
          (close-port socket)))))

  (with-mutex %http-server-lock
    (let ((server (make-thread server-body)))
      (wait-condition-variable %http-server-ready %http-server-lock)
      ;; Normally SERVER exits automatically once it has received a request.
      (parameterize ((%http-server-port %http-real-server-port))
        (thunk)))))

(define-syntax with-http-server
  (syntax-rules ()
    ((_ responses+data body ...)
     (call-with-http-server responses+data (lambda () body ...)))))

;;; http.scm ends here


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 transformations)
  #:use-module (guix i18n)
  #:use-module (guix store)
  #:use-module (guix packages)
  #:use-module (guix profiles)
  #:use-module (guix diagnostics)
  #:autoload   (guix download) (download-to-store)
  #:autoload   (guix git-download) (git-reference? git-reference-url)
  #:autoload   (guix git) (git-checkout git-checkout? git-checkout-url)
  #:autoload   (guix upstream) (package-latest-release
                                upstream-source-version
                                upstream-source-signature-urls)
  #:use-module (guix utils)
  #:use-module (guix memoization)
  #:use-module (guix gexp)

  ;; Use the procedure that destructures "NAME-VERSION" forms.
  #:use-module ((guix build utils)
                #:select ((package-name->name+version
                           . hyphen-package-name->name+version)))

  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-37)
  #:use-module (ice-9 match)
  #:use-module (ice-9 vlist)
  #:export (options->transformation
            manifest-entry-with-transformations

            show-transformation-options-help
            %transformation-options))

;;; Commentary:
;;;
;;; This module implements "package transformation options"---tools for
;;; package graph rewriting.  It contains the graph rewriting logic, but also
;;; the tip of its user interface: command-line option handling.
;;;
;;; Code:

(module-autoload! (current-module) '(gnu packages)
                  '(specification->package))

(define (numeric-extension? file-name)
  "Return true if FILE-NAME ends with digits."
  (string-every char-set:hex-digit (file-extension file-name)))

(define (tarball-base-name file-name)
  "Return the \"base\" of FILE-NAME, removing '.tar.gz' or similar
extensions."
  ;; TODO: Factorize.
  (cond ((not (file-extension file-name))
         file-name)
        ((numeric-extension? file-name)
         file-name)
        ((string=? (file-extension file-name) "tar")
         (file-sans-extension file-name))
        ((file-extension file-name)
         =>
         (match-lambda
           ("scm" file-name)
           (_     (tarball-base-name (file-sans-extension file-name)))))
        (else
         file-name)))

;; Files to be downloaded.
(define-record-type <downloaded-file>
  (downloaded-file uri recursive?)
  downloaded-file?
  (uri        downloaded-file-uri)
  (recursive? downloaded-file-recursive?))

(define download-to-store*
  (store-lift download-to-store))

(define-gexp-compiler (compile-downloaded-file (file <downloaded-file>)
                                               system target)
  "Download FILE and return the result as a store item."
  (match file
    (($ <downloaded-file> uri recursive?)
     (download-to-store* uri #:recursive? recursive?))))

(define* (package-with-source p uri #:optional version)
  "Return a package based on P but with its source taken from URI.  Extract
the new package's version number from URI."
  (let ((base (tarball-base-name (basename uri))))
    (let-values (((_ version*)
                  (hyphen-package-name->name+version base)))
      (package (inherit p)
               (version (or version version*
                            (package-version p)))

               ;; Use #:recursive? #t to allow for directories.
               (source (downloaded-file uri #t))))))

;;;
;;; Transformations.
;;;

(define (transform-package-source sources)
  "Return a transformation procedure that replaces package sources with the
matching URIs given in SOURCES."
  (define new-sources
    (map (lambda (uri)
           (match (string-index uri #\=)
             (#f
              ;; Determine the package name and version from URI.
              (call-with-values
                  (lambda ()
                    (hyphen-package-name->name+version
                     (tarball-base-name (basename uri))))
                (lambda (name version)
                  (list name version uri))))
             (index
              ;; What's before INDEX is a "PKG@VER" or "PKG" spec.
              (call-with-values
                  (lambda ()
                    (package-name->name+version (string-take uri index)))
                (lambda (name version)
                  (list name version
                        (string-drop uri (+ 1 index))))))))
         sources))

  (lambda (obj)
    (let loop ((sources  new-sources)
               (result   '()))
      (match obj
        ((? package? p)
         (match (assoc-ref sources (package-name p))
           ((version source)
            (package-with-source p source version))
           (#f
            p)))
        (_
         obj)))))

(define (evaluate-replacement-specs specs proc)
  "Parse SPECS, a list of strings like \"guile=guile@2.1\" and return a list
of package spec/procedure pairs as expected by 'package-input-rewriting/spec'.
PROC is called with the package to be replaced and its replacement according
to SPECS.  Raise an error if an element of SPECS uses invalid syntax, or if a
package it refers to could not be found."
  (define not-equal
    (char-set-complement (char-set #\=)))

  (map (lambda (spec)
         (match (string-tokenize spec not-equal)
           ((spec new)
            (cons spec
                  (let ((new (specification->package new)))
                    (lambda (old)
                      (proc old new)))))
           (x
            (raise (formatted-message
                    (G_ "invalid replacement specification: ~s")
                    spec)))))
       specs))

(define (transform-package-inputs replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"guile=guile@2.1\" meaning that, any dependency on a package
called \"guile\" must be replaced with a dependency on a version 2.1 of
\"guile\"."
  (let* ((replacements (evaluate-replacement-specs replacement-specs
                                                   (lambda (old new)
                                                     new)))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define (transform-package-inputs/graft replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"gnutls=gnutls@3.5.4\" meaning that packages are built using the
current 'gnutls' package, after which version 3.5.4 is grafted onto them."
  (define (set-replacement old new)
    (package (inherit old) (replacement new)))

  (let* ((replacements (evaluate-replacement-specs replacement-specs
                                                   set-replacement))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define %not-equal
  (char-set-complement (char-set #\=)))

(define (package-git-url package)
  "Return the URL of the Git repository for package, or raise an error if
the source of PACKAGE is not fetched from a Git repository."
  (let ((source (package-source package)))
    (cond ((and (origin? source)
                (git-reference? (origin-uri source)))
           (git-reference-url (origin-uri source)))
          ((git-checkout? source)
           (git-checkout-url source))
          (else
           (raise
            (formatted-message (G_ "the source of ~a is not a Git reference")
                               (package-full-name package)))))))

(define (evaluate-git-replacement-specs specs proc)
  "Parse SPECS, a list of strings like \"guile=stable-2.2\", and return a list
of package pairs, where (PROC PACKAGE URL BRANCH-OR-COMMIT) returns the
replacement package.  Raise an error if an element of SPECS uses invalid
syntax, or if a package it refers to could not be found."
  (map (lambda (spec)
         (match (string-tokenize spec %not-equal)
           ((spec branch-or-commit)
            (define (replace old)
              (let* ((source (package-source old))
                     (url    (package-git-url old)))
                (proc old url branch-or-commit)))

            (cons spec replace))
           (_
            (raise
             (formatted-message (G_ "invalid replacement specification: ~s")
                                spec)))))
       specs))

(define (transform-package-source-branch replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"guile-next=stable-3.0\" meaning that packages are built using
'guile-next' from the latest commit on its 'stable-3.0' branch."
  (define (replace old url branch)
    (package
      (inherit old)
      (version (string-append "git." (string-map (match-lambda
                                                   (#\/ #\-)
                                                   (chr chr))
                                                 branch)))
      (source (git-checkout (url url) (branch branch)
                            (recursive? #t)))))

  (let* ((replacements (evaluate-git-replacement-specs replacement-specs
                                                       replace))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define (transform-package-source-commit replacement-specs)
  "Return a procedure that, when passed a package, replaces its direct
dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
strings like \"guile-next=cabba9e\" meaning that packages are built using
'guile-next' from commit 'cabba9e'."
  (define (replace old url commit)
    (package
      (inherit old)
      (version (if (and (> (string-length commit) 1)
                        (string-prefix? "v" commit)
                        (char-set-contains? char-set:digit
                                            (string-ref commit 1)))
                   (string-drop commit 1)        ;looks like a tag like "v1.0"
                   (string-append "git."
                                  (if (< (string-length commit) 7)
                                      commit
                                      (string-take commit 7)))))
      (source (git-checkout (url url) (commit commit)
                            (recursive? #t)))))

  (let* ((replacements (evaluate-git-replacement-specs replacement-specs
                                                       replace))
         (rewrite      (package-input-rewriting/spec replacements)))
    (lambda (obj)
      (if (package? obj)
          (rewrite obj)
          obj))))

(define (transform-package-source-git-url replacement-specs)
  "Return a procedure that, when passed a package, replaces its dependencies
according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of strings like
\"guile-json=https://gitthing.com/…\" meaning that packages are built using
a checkout of the Git repository at the given URL."
  (define replacements
    (map (lambda (spec)
           (match (string-tokenize spec %not-equal)
             ((spec url)
              (cons spec
                    (lambda (old)
                      (package
                        (inherit old)
                        (source (git-checkout (url url)
                                              (recursive? #t)))))))
             (_
              (raise
               (formatted-message
                (G_ "~a: invalid Git URL replacement specification")
                spec)))))
         replacement-specs))

  (define rewrite
    (package-input-rewriting/spec replacements))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (package-dependents/spec top bottom)
  "Return the list of dependents of BOTTOM, a spec string, that are also
dependencies of TOP, a package."
  (define-values (name version)
    (package-name->name+version bottom))

  (define dependent?
    (mlambda (p)
      (and (package? p)
           (or (and (string=? name (package-name p))
                    (or (not version)
                        (version-prefix? version (package-version p))))
               (match (bag-direct-inputs (package->bag p))
                 (((labels dependencies . _) ...)
                  (any dependent? dependencies)))))))

  (filter dependent? (package-closure (list top))))

(define (package-toolchain-rewriting p bottom toolchain)
  "Return a procedure that, when passed a package that's either BOTTOM or one
of its dependents up to P so, changes it so it is built with TOOLCHAIN.
TOOLCHAIN must be an input list."
  (define rewriting-property
    (gensym " package-toolchain-rewriting"))

  (match (package-dependents/spec p bottom)
    (()                                           ;P does not depend on BOTTOM
     identity)
    (set
     ;; SET is the list of packages "between" P and BOTTOM (included) whose
     ;; toolchain needs to be changed.
     (package-mapping (lambda (p)
                        (if (or (assq rewriting-property
                                      (package-properties p))
                                (not (memq p set)))
                            p
                            (let ((p (package-with-c-toolchain p toolchain)))
                              (package/inherit p
                                (properties `((,rewriting-property . #t)
                                              ,@(package-properties p)))))))
                      (lambda (p)
                        (or (assq rewriting-property (package-properties p))
                            (not (memq p set))))
                      #:deep? #t))))

(define (transform-package-toolchain replacement-specs)
  "Return a procedure that, when passed a package, changes its toolchain or
that of its dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is
a list of strings like \"fftw=gcc-toolchain@10\" meaning that the package to
the left of the equal sign must be built with the toolchain to the right of
the equal sign."
  (define split-on-commas
    (cute string-tokenize <> (char-set-complement (char-set #\,))))

  (define (specification->input spec)
    (let ((package (specification->package spec)))
      (list (package-name package) package)))

  (define replacements
    (map (lambda (spec)
           (match (string-tokenize spec %not-equal)
             ((spec (= split-on-commas toolchain))
              (cons spec (map specification->input toolchain)))
             (_
              (raise
               (formatted-message
                (G_ "~a: invalid toolchain replacement specification")
                spec)))))
         replacement-specs))

  (lambda (obj)
    (if (package? obj)
        (or (any (match-lambda
                   ((bottom . toolchain)
                    ((package-toolchain-rewriting obj bottom toolchain) obj)))
                 replacements)
            obj)
        obj)))

(define (transform-package-with-debug-info specs)
  "Return a procedure that, when passed a package, set its 'replacement' field
to the same package but with #:strip-binaries? #f in its 'arguments' field."
  (define (non-stripped p)
    (package
      (inherit p)
      (arguments
       (substitute-keyword-arguments (package-arguments p)
         ((#:strip-binaries? _ #f) #f)))))

  (define (package-with-debug-info p)
    (if (member "debug" (package-outputs p))
        p
        (let loop ((p p))
          (match (package-replacement p)
            (#f
             (package
               (inherit p)
               (replacement (non-stripped p))))
            (next
             (package
               (inherit p)
               (replacement (loop next))))))))

  (define rewrite
    (package-input-rewriting/spec (map (lambda (spec)
                                         (cons spec package-with-debug-info))
                                       specs)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (transform-package-tests specs)
  "Return a procedure that, when passed a package, sets #:tests? #f in its
'arguments' field."
  (define (package-without-tests p)
    (package/inherit p
      (arguments
       (substitute-keyword-arguments (package-arguments p)
         ((#:tests? _ #f) #f)))))

  (define rewrite
    (package-input-rewriting/spec (map (lambda (spec)
                                         (cons spec package-without-tests))
                                       specs)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (transform-package-patches specs)
  "Return a procedure that, when passed a package, returns a package with
additional patches."
  (define (package-with-extra-patches p patches)
    (if (origin? (package-source p))
        (package/inherit p
          (source (origin
                    (inherit (package-source p))
                    (patches (append (map (lambda (file)
                                            (local-file file))
                                          patches)
                                     (origin-patches (package-source p)))))))
        p))

  (define (coalesce-alist alist)
    ;; Coalesce multiple occurrences of the same key in ALIST.
    (let loop ((alist alist)
               (keys '())
               (mapping vlist-null))
      (match alist
        (()
         (map (lambda (key)
                (cons key (vhash-fold* cons '() key mapping)))
              (delete-duplicates (reverse keys))))
        (((key . value) . rest)
         (loop rest
               (cons key keys)
               (vhash-cons key value mapping))))))

  (define patches
    ;; Spec/patch alist.
    (coalesce-alist
     (map (lambda (spec)
            (match (string-tokenize spec %not-equal)
              ((spec patch)
               (cons spec (canonicalize-path patch)))
              (_
               (raise (formatted-message
                       (G_ "~a: invalid package patch specification")
                       spec)))))
          specs)))

  (define rewrite
    (package-input-rewriting/spec
     (map (match-lambda
            ((spec . patches)
             (cons spec (cut package-with-extra-patches <> patches))))
          patches)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define (transform-package-latest specs)
  "Return a procedure that rewrites package graphs such that those in SPECS
are replaced by their latest upstream version."
  (define (package-with-latest-upstream p)
    (let ((source (package-latest-release p)))
      (cond ((not source)
             (warning
              (G_ "could not determine latest upstream release of '~a'~%")
              (package-name p))
             p)
            ((string=? (upstream-source-version source)
                       (package-version p))
             p)
            (else
             (unless (pair? (upstream-source-signature-urls source))
               (warning (G_ "cannot authenticate source of '~a', version ~a~%")
                        (package-name p)
                        (upstream-source-version source)))

             ;; TODO: Take 'upstream-source-input-changes' into account.
             (package
               (inherit p)
               (version (upstream-source-version source))
               (source source))))))

  (define rewrite
    (package-input-rewriting/spec
     (map (lambda (spec)
            (cons spec package-with-latest-upstream))
          specs)))

  (lambda (obj)
    (if (package? obj)
        (rewrite obj)
        obj)))

(define %transformations
  ;; Transformations that can be applied to things to build.  The car is the
  ;; key used in the option alist, and the cdr is the transformation
  ;; procedure; it is called with two arguments: the store, and a list of
  ;; things to build.
  `((with-source . ,transform-package-source)
    (with-input  . ,transform-package-inputs)
    (with-graft  . ,transform-package-inputs/graft)
    (with-branch . ,transform-package-source-branch)
    (with-commit . ,transform-package-source-commit)
    (with-git-url . ,transform-package-source-git-url)
    (with-c-toolchain . ,transform-package-toolchain)
    (with-debug-info . ,transform-package-with-debug-info)
    (without-tests . ,transform-package-tests)
    (with-patch  . ,transform-package-patches)
    (with-latest . ,transform-package-latest)))

(define (transformation-procedure key)
  "Return the transformation procedure associated with KEY, a symbol such as
'with-source', or #f if there is none."
  (any (match-lambda
         ((k . proc)
          (and (eq? k key) proc)))
       %transformations))

;;;
;;; Command-line handling.
;;;

(define %transformation-options
  ;; The command-line interface to the above transformations.
  (let ((parser (lambda (symbol)
                  (lambda (opt name arg result . rest)
                    (apply values
                           (alist-cons symbol arg result)
                           rest)))))
    (list (option '("with-source") #t #f
                  (parser 'with-source))
          (option '("with-input") #t #f
                  (parser 'with-input))
          (option '("with-graft") #t #f
                  (parser 'with-graft))
          (option '("with-branch") #t #f
                  (parser 'with-branch))
          (option '("with-commit") #t #f
                  (parser 'with-commit))
          (option '("with-git-url") #t #f
                  (parser 'with-git-url))
          (option '("with-c-toolchain") #t #f
                  (parser 'with-c-toolchain))
          (option '("with-debug-info") #t #f
                  (parser 'with-debug-info))
          (option '("without-tests") #t #f
                  (parser 'without-tests))
          (option '("with-patch") #t #f
                  (parser 'with-patch))
          (option '("with-latest") #t #f
                  (parser 'with-latest))

          (option '("help-transform") #f #f
                  (lambda _
                    (format #t
                            (G_ "Available package transformation options:~%"))
                    (show-transformation-options-help/detailed)
                    (newline)
                    (exit 0))))))

(define (show-transformation-options-help/detailed)
  (display (G_ "
      --with-source=[PACKAGE=]SOURCE
                         use SOURCE when building the corresponding package"))
  (display (G_ "
      --with-input=PACKAGE=REPLACEMENT
                         replace dependency PACKAGE by REPLACEMENT"))
  (display (G_ "
      --with-graft=PACKAGE=REPLACEMENT
                         graft REPLACEMENT on packages that refer to PACKAGE"))
  (display (G_ "
      --with-branch=PACKAGE=BRANCH
                         build PACKAGE from the latest commit of BRANCH"))
  (display (G_ "
      --with-commit=PACKAGE=COMMIT
                         build PACKAGE from COMMIT"))
  (display (G_ "
      --with-git-url=PACKAGE=URL
                         build PACKAGE from the repository at URL"))
  (display (G_ "
      --with-patch=PACKAGE=FILE
                         add FILE to the list of patches of PACKAGE"))
  (display (G_ "
      --with-latest=PACKAGE
                         use the latest upstream release of PACKAGE"))
  (display (G_ "
      --with-c-toolchain=PACKAGE=TOOLCHAIN
                         build PACKAGE and its dependents with TOOLCHAIN"))
  (display (G_ "
      --with-debug-info=PACKAGE
                         build PACKAGE and preserve its debug info"))
  (display (G_ "
      --without-tests=PACKAGE
                         build PACKAGE without running its tests")))

(define (show-transformation-options-help)
  "Show basic help for package transformation options."
  (display (G_ "
      --help-transform   list package transformation options not shown here")))

(define (options->transformation opts)
  "Return a procedure that, when passed an object to build (package,
derivation, etc.), applies the transformations specified by OPTS and returns
the resulting objects.  OPTS must be a list of symbol/string pairs such as:

  ((with-branch . \"guile-gcrypt=master\")
   (without-tests . \"libgcrypt\"))

Each symbol names a transformation and the corresponding string is an argument
to that transformation."
  (define applicable
    ;; List of applicable transformations as symbol/procedure pairs in the
    ;; order in which they appear on the command line.
    (filter-map (match-lambda
                  ((key . value)
                   (match (transformation-procedure key)
                     (#f
                      #f)
                     (transform
                      ;; XXX: We used to pass TRANSFORM a list of several
                      ;; arguments, but we now pass only one, assuming that
                      ;; transform composes well.
                      (list key value (transform (list value)))))))
                (reverse opts)))

  (define (package-with-transformation-properties p)
    (package/inherit p
      (properties `((transformations
                     . ,(map (match-lambda
                               ((key value _)
                                (cons key value)))
                             applicable))
                    ,@(package-properties p)))))

  (lambda (obj)
    (define (tagged-object new)
      (if (and (not (eq? obj new))
               (package? new) (not (null? applicable)))
          (package-with-transformation-properties new)
          new))

    (tagged-object
     (fold (match-lambda*
             (((name value transform) obj)
              (let ((new (transform obj)))
                (when (eq? new obj)
                  (warning (G_ "transformation '~a' had no effect on ~a~%")
                           name
                           (if (package? obj)
                               (package-full-name obj)
                               obj)))
                new)))
           obj
           applicable))))

(define (package-transformations package)
  "Return the transformations applied to PACKAGE according to its properties."
  (match (assq-ref (package-properties package) 'transformations)
    (#f '())
    (transformations transformations)))

(define (manifest-entry-with-transformations entry)
  "Return ENTRY with an additional 'transformations' property if it's not
already there."
  (let ((properties (manifest-entry-properties entry)))
    (if (assq 'transformations properties)
        entry
        (let ((item (manifest-entry-item entry)))
          (manifest-entry
            (inherit entry)
            (properties
             (match (and (package? item)
                         (package-transformations item))
               ((or #f '())
                properties)
               (transformations
                `((transformations . ,transformations)
                  ,@properties)))))))))