diff --git a/gnu/packages/astronomy.scm b/gnu/packages/astronomy.scm
index d9ade1ea96a..1bd9724293e 100644
--- a/gnu/packages/astronomy.scm
+++ b/gnu/packages/astronomy.scm
@@ -1890,18 +1890,9 @@ R. Seaman's protocol}
          (file-name (git-file-name name version))
          (sha256
           (base32 "0n2jzlpwvjgj8ydg7hsqxnvy8s9pdi5z96id0231kgi87pyfkh7s"))
-         (modules '((guix build utils)
-                    (ice-9 ftw)
-                    (srfi srfi-26)))
+         (modules '((guix build utils)))
          (snippet
           #~(begin
-              ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-              (define (delete-all-but directory . preserve)
-                (with-directory-excursion directory
-                  (let* ((pred (negate (cut member <>
-                                            (cons* "." ".." preserve))))
-                         (items (scandir "." pred)))
-                    (for-each (cut delete-file-recursively <>) items))))
               (delete-all-but "thirdparty" "thirdparty.cmake")))))
       (build-system cmake-build-system)
       (arguments
diff --git a/gnu/packages/electronics.scm b/gnu/packages/electronics.scm
index 999fdc971a7..acb70560ea6 100644
--- a/gnu/packages/electronics.scm
+++ b/gnu/packages/electronics.scm
@@ -1282,18 +1282,9 @@ understand and improve testbench coverage.")
                 ;; no longer have their original upstream.
                 (recursive? #t)))
          (file-name (git-file-name name version))
-         (modules '((guix build utils)
-                    (ice-9 ftw)
-                    (srfi srfi-26)))
+         (modules '((guix build utils)))
          (snippet
           '(begin
-             ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-             (define (delete-all-but directory . preserve)
-               (with-directory-excursion directory
-                 (let* ((pred (negate (cut member <>
-                                           (cons* "." ".." preserve))))
-                        (items (scandir "." pred)))
-                   (for-each (cut delete-file-recursively <>) items))))
              (delete-all-but "3rdparty"
                              ;; The following sources have all been patched, so
                              ;; cannot easily be unbundled.
diff --git a/gnu/packages/emacs-xyz.scm b/gnu/packages/emacs-xyz.scm
index dfe29e58bb1..5fc4519b056 100644
--- a/gnu/packages/emacs-xyz.scm
+++ b/gnu/packages/emacs-xyz.scm
@@ -15375,18 +15375,9 @@ placed at the margin of the minibuffer for your completion candidates.")
                (url "https://github.com/Fuco1/smartparens")
                (commit commit)))
          (file-name (git-file-name name version))
-         (modules '((guix build utils)
-                    (ice-9 ftw)
-                    (srfi srfi-26)))
+         (modules '((guix build utils)))
          (snippet
           '(begin
-             ;; Taken from nextpnr package.
-             (define (delete-all-but directory . preserve)
-               (with-directory-excursion directory
-                 (let* ((pred
-                         (negate (cut member <> (append '("." "..") preserve))))
-                        (items (scandir "." pred)))
-                   (for-each delete-file items))))
              ;; Only activate basic tests.
              (delete-all-but "test"
                              "test-helper.el"
diff --git a/gnu/packages/emulators.scm b/gnu/packages/emulators.scm
index 7e1ce2a797f..8e1cecc7f5d 100644
--- a/gnu/packages/emulators.scm
+++ b/gnu/packages/emulators.scm
@@ -452,13 +452,6 @@ It aims to support Nintendo DSi and 3DS as well.")
                     (srfi srfi-26)))
          (snippet
           #~(begin
-              (define (delete-all-but directory . preserve)
-                (with-directory-excursion directory
-                  (let* ((pred (negate (cut member <>
-                                            (cons* "." ".." preserve))))
-                         (items (scandir "." pred)))
-                    (for-each (cut delete-file-recursively <>) items))))
-
               ;; Clean up the source from bundled libraries we don't need.
               (delete-all-but "Externals"
                               ;; XXX: The build system is currently hard-coded
@@ -648,14 +641,6 @@ turbo speed, networked multiplayer, and graphical enhancements.")
                     (srfi srfi-26)))
          (snippet
           #~(begin
-              ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-              (define (delete-all-but directory . preserve)
-                (with-directory-excursion directory
-                  (let* ((pred (negate (cut member <>
-                                            (cons* "." ".." preserve))))
-                         (items (scandir "." pred)))
-                    (for-each (cut delete-file-recursively <>) items))))
-
               ;; Clean up the source from bundled libraries we don't need.
               (delete-all-but "Externals"
                               ;; XXX: The build system is currently hard-coded
@@ -1071,17 +1056,9 @@ The following systems are supported:
          (sha256
           (base32
            "0dfsz4dsh49dc9xx9rjhfzfkg4h91i2ksgp2inlr9yhgldw9q8h3"))
-         (modules '((guix build utils)
-                    (ice-9 ftw)
-                    (srfi srfi-26)))
+         (modules '((guix build utils)))
          (snippet
           #~(begin
-              (define (delete-all-but directory . preserve)
-                (with-directory-excursion directory
-                  (let* ((pred (negate (cut member <> (cons* "." ".." preserve))))
-                         (items (scandir "." pred)))
-                    (for-each (cut delete-file-recursively <>) items))))
-
               (delete-all-but "src/third-party"
                               "blip_buf"
                               "inih")))))
@@ -2833,16 +2810,7 @@ GLSL (@file{.slang}) shaders for use with RetroArch.")
              (commit (string-append "v" version))))
        (snippet
         #~(begin
-            (use-modules (guix build utils)
-                         (ice-9 ftw)
-                         (srfi srfi-26))
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
+            (use-modules (guix build utils))
             ;; Remove as much bundled sources as possible, shaving off about
             ;; 65 MiB.
             (delete-all-but "deps"
diff --git a/gnu/packages/game-development.scm b/gnu/packages/game-development.scm
index ff72864e77c..95c321a8f27 100644
--- a/gnu/packages/game-development.scm
+++ b/gnu/packages/game-development.scm
@@ -1136,17 +1136,9 @@ It is capable of creating games for SCUMM version 6 and partially version 7.")
        (sha256
         (base32
          "12f1d45995qf5sazjmmfdydllcd6alhqs1s4xwv3jiq1fw66hcy9"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         '(begin
-           ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-           (define (delete-all-but directory . preserve)
-             (with-directory-excursion directory
-               (let* ((pred (negate (cut member <> (cons* "." ".." preserve))))
-                      (items (scandir "." pred)))
-                 (for-each (cut delete-file-recursively <>) items))))
            (delete-all-but "extlibs/headers"
                            "glad")))))  ;pre-generated headers
     (build-system cmake-build-system)
diff --git a/gnu/packages/golang-build.scm b/gnu/packages/golang-build.scm
index ff0c0544d2f..1646b7119d3 100644
--- a/gnu/packages/golang-build.scm
+++ b/gnu/packages/golang-build.scm
@@ -1491,17 +1491,9 @@ Go programming language.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0sjvngpahkb5x573i855fjlb1fdmr6n269nmb5xxnbabjb27mnvg"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "go" "expect")
             (delete-all-but "." "go")))))
     (build-system go-build-system)
@@ -1531,17 +1523,9 @@ Go source code (including go.mod and go.work files) as test expectations.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0sjvngpahkb5x573i855fjlb1fdmr6n269nmb5xxnbabjb27mnvg"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "go" "packages")
             (delete-all-but "go/packages" "packagestest")
             (delete-all-but "." "go")))))
@@ -1574,18 +1558,9 @@ tools on.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1blk22apy424j9v58lfy4pxnrgh93yqchqhxsnf78dmx4vx5yi9r"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "godoc")))))
+        #~(begin (delete-all-but "." "godoc")))))
     (build-system go-build-system)
     (arguments
      (list
diff --git a/gnu/packages/golang-web.scm b/gnu/packages/golang-web.scm
index 96109e7007c..1e30e7500f7 100644
--- a/gnu/packages/golang-web.scm
+++ b/gnu/packages/golang-web.scm
@@ -230,16 +230,8 @@ devices.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0i18wkz04w9wpckw021nawr82dh92krmcsn471rpjx1jrmgsbi5v"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-file-recursively "auth/oauth2adapt")
                     (delete-all-but "." "auth")))))
     (build-system go-build-system)
@@ -294,16 +286,8 @@ automatic token management.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "109szg097fn42qpsmrmd29iwsdh2yrjh9krq8mjm02fnm7l18lc4"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-all-but "auth" "oauth2adapt")
                     (delete-all-but "." "auth")))))
     (build-system go-build-system)
@@ -1576,20 +1560,9 @@ parameter types for AWS Secrets Manager.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "07g7vgpkq8cqirc2s64d9yswnpzdb7jzqr5kwrpblya2nq27inml"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "service" "sqs")
             (delete-all-but "." "service")))))
     (build-system go-build-system)
@@ -1871,16 +1844,8 @@ the OTEL Go SDK.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1qbcm8mqg2qvikv129s832qqvpydipv71825s4dkyjmzar5g04vf"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-all-but "sdk" "azcore")
                     (delete-all-but "." "sdk")))))
     (build-system go-build-system)
@@ -1914,16 +1879,8 @@ Azure SDK clients.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "18s9h2fcbcw39idfyjglm7vyyp04bgl0x0wj4vcd8q6a46b8rbh6"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-all-but "sdk" "azidentity")
                     (delete-all-but "." "sdk")))))
     (build-system go-build-system)
@@ -1964,16 +1921,8 @@ clients supporting token authentication.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "08a8kx4n31pa4krrxs1hrcwygryh86nz98fyr9hvw67202zr3adw"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-all-but "sdk/storage" "azblob")
                     (delete-all-but "sdk" "storage")
                     (delete-all-but "." "sdk")))))
@@ -2014,16 +1963,8 @@ to Azure Blob Storage}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "08a8kx4n31pa4krrxs1hrcwygryh86nz98fyr9hvw67202zr3adw"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-all-but "sdk/storage" "azfile")
                     (delete-all-but "sdk" "storage")
                     (delete-all-but "." "sdk")))))
@@ -2067,16 +2008,8 @@ used.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0q0cbmh4vn2x1bi7bax2q6wpqndcyw7649w8lzl384k3rbn1q8yn"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet #~(begin
-                    (define (delete-all-but directory . preserve)
-                      (with-directory-excursion directory
-                        (let* ((pred (negate (cut member <>
-                                                  (cons* "." ".." preserve))))
-                               (items (scandir "." pred)))
-                          (for-each (cut delete-file-recursively <>) items))))
                     (delete-all-but "sdk" "internal")
                     (delete-all-but "." "sdk")))))
     (build-system go-build-system)
@@ -9843,18 +9776,9 @@ control the daemon.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1624z57hqqw1b473arfa5m936rsrhc8h3hs2jg4645b3dykfyawn"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "client")))))
+        #~(begin (delete-all-but "." "client")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -15010,20 +14934,9 @@ Handler) and routes @code{WithRouteTag}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "15k2xps4qv37pw3ml6pj98kihl6a04bbr005px5hhckl23s40w2c"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "propagators" "autoprop")
             (delete-all-but "." "propagators")))))
     (build-system go-build-system)
@@ -15291,20 +15204,9 @@ go.opentelemetry.io/otel/trace.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1kvfbqc56p1h9rh9cvgn37ya6k10613r0f2rhjiwrrkgs2mszk30"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "exporters/otlp" "otlptrace")
             (delete-all-but "." "exporters")
             ;; Submodules with their own go.mod files and packed as separated
@@ -15346,20 +15248,12 @@ go.opentelemetry.io/otel/trace.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1kvfbqc56p1h9rh9cvgn37ya6k10613r0f2rhjiwrrkgs2mszk30"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
             ;; XXX: 'delete-all-but' is copied from the turbovnc package.
             ;; Consider to implement it as re-usable procedure in
             ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "exporters/otlp/otlptrace" "otlptracegrpc")
             (delete-all-but "." "exporters")))))
     (build-system go-build-system)
@@ -15402,20 +15296,9 @@ By default the telemetry is sent to @@url{https://localhost:4317}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1kvfbqc56p1h9rh9cvgn37ya6k10613r0f2rhjiwrrkgs2mszk30"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "exporters/otlp/otlptrace" "otlptracehttp")
             (delete-all-but "." "exporters")))))
     (build-system go-build-system)
@@ -15489,20 +15372,9 @@ telemetry to be written to an output destination as JSON.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1kvfbqc56p1h9rh9cvgn37ya6k10613r0f2rhjiwrrkgs2mszk30"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "exporters" "zipkin")
             (delete-all-but "." "exporters")))))
     (build-system go-build-system)
@@ -15537,20 +15409,9 @@ telemetry to be written to an output destination as JSON.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0sb36qyq389fif9qp5iiqp6w41dfcwi95gb0bsbvznvijhd8c1cc"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "." "log")))))
     (build-system go-build-system)
     (arguments
@@ -15596,20 +15457,9 @@ OpenTelemetry API.")))
        (file-name (git-file-name name version))
        (sha256
         (base32 "0sb36qyq389fif9qp5iiqp6w41dfcwi95gb0bsbvznvijhd8c1cc"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "." "sdk")
             (delete-file-recursively "sdk/log")
             (delete-file-recursively "sdk/metric")))))
@@ -15646,20 +15496,9 @@ OpenTelemetry API.")))
        (file-name (git-file-name name version))
        (sha256
         (base32 "0sb36qyq389fif9qp5iiqp6w41dfcwi95gb0bsbvznvijhd8c1cc"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "sdk" "log")
             (delete-all-but "." "sdk")))))
     (build-system go-build-system)
@@ -15694,20 +15533,9 @@ OpenTelemetry API.")))
        (file-name (git-file-name name version))
        (sha256
         (base32 "0sb36qyq389fif9qp5iiqp6w41dfcwi95gb0bsbvznvijhd8c1cc"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "sdk" "metric")
             (delete-all-but "." "sdk")))))
     (build-system go-build-system)
@@ -15796,18 +15624,9 @@ maturity level}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "155qcbl84bwy7m9k221w75yakfv71fbxpfn9g3d7nnq6cl30fbfw"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "sdk")))))
+        #~(begin (delete-all-but "." "sdk")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -16056,20 +15875,9 @@ the standard @code{context} package to store request-scoped values.")
        (uri (git-reference
               (url "https://github.com/googleapis/go-genproto")
               (commit (go-version->git-ref version #:subdir "googleapis/api"))))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             ;; Submodules with their own go.mod files and packaged separately:
             ;;
             ;; - google.golang.org/genproto/googleapis/api/apikeys
@@ -16185,18 +15993,9 @@ the standard @code{context} package to store request-scoped values.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0yn1ir5y0wc91q95ngr3dlz2cyhp0wlb9l30hkw2cr34r38hq19w"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "cmd")))))
+        #~(begin (delete-all-but "." "cmd")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -16460,18 +16259,9 @@ the code or routes.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1appaqgllddcl6kxkz3azix0xhlzy093vvxi6y3im1mkf5zblwl7"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "test")))))
+        #~(begin (delete-all-but "." "test")))))
     (build-system go-build-system)
     (arguments
      (list
diff --git a/gnu/packages/golang-xyz.scm b/gnu/packages/golang-xyz.scm
index de9afb131af..f2297cd4b29 100644
--- a/gnu/packages/golang-xyz.scm
+++ b/gnu/packages/golang-xyz.scm
@@ -3827,18 +3827,9 @@ glamorous default themes.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "083zj3yqb48li8w389iabi1b1zklbw7cwam2grvvglcqrrsj3bsf"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "ansi")))))
+        #~(begin (delete-all-but "." "ansi")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -3875,14 +3866,7 @@ ECMA-48} specs.")
                   (ice-9 ftw)
                   (srfi srfi-26)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "cellbuf")))))
+        #~(begin (delete-all-but "." "cellbuf")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -4015,18 +3999,9 @@ package provides an API for comparing Golden files.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1shw55110fnn4xz80wmgr18czmiil6z1j064m90iw8c7j9llfzn5"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "term")))))
+        #~(begin (delete-all-but "." "term")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -5014,21 +4989,9 @@ packages.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0afaljkkd388f6igr3f2vjnd14yr8h20fcfzglw8j5q1q7a1cvik"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "pkg")))))
+        #~(begin (delete-all-but "." "pkg")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -12865,18 +12828,9 @@ Twisted's manhole library} .")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0xj782ghf0iv8r2xxmg2vrh72b02h216y4yfyi60y9z0691lrsip"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "tools")))))
+        #~(begin (delete-all-but "." "tools")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -16160,18 +16114,9 @@ publish–subscribe pattern}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "0an8ypp8v9gfxbbb71mpimb1g9labl4v7lgazcphysn6c5smgmiw"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "atomicwriter")))))
+        #~(begin (delete-all-but "." "atomicwriter")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -16226,18 +16171,9 @@ https://github.com/syndtr/gocapability.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "1nh1disclgydvq7k10awzks6k8kw9cjj3q19f83ksi4b76p5l475"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "mount")))))
+        #~(begin (delete-all-but "." "mount")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -25724,21 +25660,9 @@ when they'd prefer a more familiar, loosely typed API.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "05i15278swdmpif3p6g18sy0sn7rnfdl3m2rj5p30cnyb0j29vig"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "exp")))))
+        #~(begin (delete-all-but "." "exp")))))
     (build-system go-build-system)
     (arguments
      (list
@@ -27010,18 +26934,9 @@ code.")
     (name "go-modernc-org-ccgo-v4")
     (source (origin
               (inherit (package-source go-modernc-org-ccgo-v3))
-              (modules '((guix build utils)
-                         (ice-9 ftw)
-                         (srfi srfi-26)))
+              (modules '((guix build utils)))
               (snippet
-               #~(begin
-                   (define (delete-all-but directory . preserve)
-                     (with-directory-excursion directory
-                       (let* ((pred (negate (cut member <>
-                                                 (cons* "." ".." preserve))))
-                              (items (scandir "." pred)))
-                         (for-each (cut delete-file-recursively <>) items))))
-                   (delete-all-but "." "v4")))))
+               #~(begin (delete-all-but "." "v4")))))
     (arguments
      (substitute-keyword-arguments
          (package-arguments go-modernc-org-ccgo-v3)
@@ -27912,20 +27827,9 @@ unmarshaling functions based on @code{encoding/json} @code{Unmarshal()}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "12n8ij4gisah5mvxcgq263iic61gjpxdj3ml03826zckzn7wlv46"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "." "cmd")
             (delete-all-but "cmd" "config")))))
     (build-system go-build-system)
diff --git a/gnu/packages/ipfs.scm b/gnu/packages/ipfs.scm
index 0ecface944f..79d0d6ffbc6 100644
--- a/gnu/packages/ipfs.scm
+++ b/gnu/packages/ipfs.scm
@@ -1509,21 +1509,9 @@ code prior to it getting merged into @code{go-cid}.")
        (file-name (git-file-name name version))
        (sha256
         (base32 "00lwizzdfdx6kynxddal3all6q9dhwqanpkw0d0vxlwik4nkvxa5"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
-        #~(begin
-            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-            ;; Consider to implement it as re-usable procedure in
-            ;; guix/build/utils or guix/build-system/go.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
-            (delete-all-but "." "ipfs")))))
+        #~(begin (delete-all-but "." "ipfs")))))
     (build-system go-build-system)
     (arguments
      (list
diff --git a/gnu/packages/mpi.scm b/gnu/packages/mpi.scm
index 89e5adec682..a0e47860cb4 100644
--- a/gnu/packages/mpi.scm
+++ b/gnu/packages/mpi.scm
@@ -351,18 +351,9 @@ software vendors, application developers and computer science researchers.")
        (uri (string-append "https://www.open-mpi.org/software/ompi/v"
                            (version-major+minor version)
                            "/downloads/openmpi-" version ".tar.bz2"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         '(begin
-           ;; XXX: 'delete-all-but' is copied from the turbovnc package.
-           (define (delete-all-but directory . preserve)
-             (with-directory-excursion directory
-               (let* ((pred (negate (cut member <>
-                                         (cons* "." ".." preserve))))
-                      (items (scandir "." pred)))
-                 (for-each (cut delete-file-recursively <>) items))))
            ;; Delete as many bundled libraries as permitted by the build
            ;; system.
            (delete-all-but "3rd-party" "treematch" "Makefile.in" "Makefile.am")
diff --git a/gnu/packages/specifications.scm b/gnu/packages/specifications.scm
index a79d1437244..228e1b19de7 100644
--- a/gnu/packages/specifications.scm
+++ b/gnu/packages/specifications.scm
@@ -46,19 +46,11 @@
        (file-name (git-file-name name version))
        (sha256
         (base32 "0iwd2q4v7qi4fc2b2dhxxkp6bpbhgdd4s5q3jx0vq52p1fh9y0ni"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         ;; XXX: Keep just some portion with valulable data and no license
         ;; issues.
         #~(begin
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
             (delete-all-but "."
                             "allsky"
                             "coordinates"
diff --git a/gnu/packages/vnc.scm b/gnu/packages/vnc.scm
index f87f0c1430c..58d89609399 100644
--- a/gnu/packages/vnc.scm
+++ b/gnu/packages/vnc.scm
@@ -182,9 +182,7 @@ RDP, VNC, SPICE, NX, XDMCP, SSH and EXEC network protocols are supported.")
        (method url-fetch)
        (uri (string-append "mirror://sourceforge/turbovnc/" version
                            "/turbovnc-" version ".tar.gz"))
-       (modules '((guix build utils)
-                  (ice-9 ftw)
-                  (srfi srfi-26)))
+       (modules '((guix build utils)))
        (snippet
         #~(begin
             ;; There are a few bundled Java libraries, such as jsch and jzlib,
@@ -192,12 +190,6 @@ RDP, VNC, SPICE, NX, XDMCP, SSH and EXEC network protocols are supported.")
             ;; bundled under java/org.  These are used by the 'vncviewer'
             ;; program.  The jsch copy is modified and integrates changes from
             ;; https://github.com/mwiede/jsch, so cannot easily be un-bundled.
-            (define (delete-all-but directory . preserve)
-              (with-directory-excursion directory
-                (let* ((pred (negate (cut member <>
-                                          (cons* "." ".." preserve))))
-                       (items (scandir "." pred)))
-                  (for-each (cut delete-file-recursively <>) items))))
 
             ;; d3des, rfb (headers) and turbojpeg-jni are small and not
             ;; packaged in Guix, so preserve them.