@@ -1017,10 +1010,31 @@ from forcing GEXP-PROMISE."
            (lambda _
              (use-modules (guix build cargo-utils))
              (let ((null-hash "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"))
-               (substitute* '("Cargo.lock" "gfx/wr/Cargo.lock")
-                 (("(\"checksum .* = )\".*\"" all name)
-                  (string-append name "\"" null-hash "\"")))
-               (generate-all-checksums "third_party/rust"))
+               (for-each (lambda (file)
+                           (format #t "patching checksums in ~a~%" file)
+                           (substitute* (find-files "." "Cargo.lock$")
+                             (("^checksum = \".*\"")
+                              (string-append "checksum = \"" null-hash "\""))))
+                         (find-files "." "Cargo.lock$"))
+               (for-each generate-all-checksums
+                         '("services"
+                           "js"
+                           "third_party/rust"
+                           "dom/media"
+                           "dom/webauthn"
+                           "toolkit"
+                           "gfx"
+                           "storage"
+                           "modules"
+                           "xpcom/rust"
+                           "media"
+                           "mozglue/static/rust"
+                           "netwerk"
+                           "remote"
+                           "intl"
+                           "servo"
+                           "security/manager/ssl"
+                           "build")))

Why we need another `find-files` in `substitute*`? The outer `find-files` should find all locks file for you, maybe you can use the arg of lambda instead.

@@ -756,8 +750,8 @@ from forcing GEXP-PROMISE."
        ("libxt" ,libxt)
        ("libffi" ,libffi)
        ("ffmpeg" ,ffmpeg)
-       ("libvpx" ,libvpx)
-       ("icu4c" ,icu4c)
+       ;; UNBUNDLE-ME! ("libvpx" ,libvpx)
+       ;; UNBUNDLE-ME! ("icu4c" ,icu4c)
        ("pixman" ,pixman)
        ("pulseaudio" ,pulseaudio)
        ("mesa" ,mesa)

IceCat 78 may need icu4c v67, which variable name is `icu4c-67` in guix channel.