[bug#77093,rust-team,v2,14/17] build-system: cargo: Add ‘cargo-inputs’.

diff --git a/etc/teams/rust/cleanup-crates.sh b/etc/teams/rust/cleanup-crates.sh
new file mode 100755
index 0000000000..cd4c2462b9
--- /dev/null
+++ b/etc/teams/rust/cleanup-crates.sh
@@ -0,0 +1,38 @@ 
+#!/bin/sh
+
+# GNU Guix --- Functional package management for GNU
+# Copyright © 2025 Hilton Chain <hako@ultrarare.space>
+#
+# 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/>.
+
+FILE=gnu/packages/rust-crates.scm
+PATTERN='^(define rust-'
+
+grep "$PATTERN" $FILE | cut -d' ' -f2 | while IFS= read -r crate
+do
+    if [ "$(grep -wc "$crate" $FILE)" -eq 1 ]; then
+        echo "\
+(begin
+  (use-modules (guix utils))
+  (let ((source-properties
+         (find-definition-location \"$FILE\" '$crate #:definer 'define)))
+    (and=> source-properties delete-expression)))" |
+            guix repl -t machine
+    fi
+done
+
+# Delete extra newlines.
+sed --in-place ':a;N;$!ba;s/\n\n\+/\n\n/g' $FILE
diff --git a/etc/teams/rust/rust-crates.tmpl b/etc/teams/rust/rust-crates.tmpl
new file mode 100644
index 0000000000..98053b7151
--- /dev/null
+++ b/etc/teams/rust/rust-crates.tmpl
@@ -0,0 +1,42 @@ 
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2025 Hilton Chain <hako@ultrarare.space>
+;;;
+;;; 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 (gnu packages rust-crates)
+  #:use-module (guix gexp)
+  #:use-module (guix packages)
+  #:use-module (guix download)
+  #:use-module (guix git-download)
+  #:use-module (guix build-system cargo))
+
+;;;
+;;; This file is managed by ‘guix import’.  DO NOT add definitions manually.
+;;;
+
+;;;
+;;; Rust dependencies fetched from crates.io and non-workspace development
+;;; snapshots.
+;;;
+
+(define qqqq-separator 'begin-of-crates)
+
+(define ssss-separator 'end-of-crates)
+
+
+;;;
+;;; Cargo inputs.
+;;;
diff --git a/gnu/local.mk b/gnu/local.mk
index 02de02e65f..8d8bd6ebbe 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -616,6 +616,8 @@  GNU_SYSTEM_MODULES =				\
   %D%/packages/rush.scm				\
   %D%/packages/rust.scm				\
   %D%/packages/rust-apps.scm			\
+  %D%/packages/rust-crates.scm			\
+  %D%/packages/rust-sources.scm			\
   %D%/packages/samba.scm			\
   %D%/packages/sagemath.scm			\
   %D%/packages/sawfish.scm			\
diff --git a/gnu/packages/rust-crates.scm b/gnu/packages/rust-crates.scm
new file mode 100644
index 0000000000..98053b7151
--- /dev/null
+++ b/gnu/packages/rust-crates.scm
@@ -0,0 +1,42 @@ 
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2025 Hilton Chain <hako@ultrarare.space>
+;;;
+;;; 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 (gnu packages rust-crates)
+  #:use-module (guix gexp)
+  #:use-module (guix packages)
+  #:use-module (guix download)
+  #:use-module (guix git-download)
+  #:use-module (guix build-system cargo))
+
+;;;
+;;; This file is managed by ‘guix import’.  DO NOT add definitions manually.
+;;;
+
+;;;
+;;; Rust dependencies fetched from crates.io and non-workspace development
+;;; snapshots.
+;;;
+
+(define qqqq-separator 'begin-of-crates)
+
+(define ssss-separator 'end-of-crates)
+
+
+;;;
+;;; Cargo inputs.
+;;;
diff --git a/gnu/packages/rust-sources.scm b/gnu/packages/rust-sources.scm
new file mode 100644
index 0000000000..bf9b91a671
--- /dev/null
+++ b/gnu/packages/rust-sources.scm
@@ -0,0 +1,29 @@ 
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2025 Hilton Chain <hako@ultrarare.space>
+;;;
+;;; 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 (gnu packages rust-sources)
+  #:use-module (guix gexp)
+  #:use-module (guix packages)
+  #:use-module (guix download)
+  #:use-module (guix git-download)
+  #:use-module (guix build-system cargo))
+
+;;;
+;;; Cargo workspaces and Rust dependencies requiring external inputs to
+;;; unbundle.
+;;;
diff --git a/guix/build-system/cargo.scm b/guix/build-system/cargo.scm
index 7a07003262..47d4f10969 100644
--- a/guix/build-system/cargo.scm
+++ b/guix/build-system/cargo.scm
@@ -31,6 +31,7 @@  (define-module (guix build-system cargo)
   #:use-module (guix gexp)
   #:use-module (guix monads)
   #:use-module (guix packages)
+  #:use-module (guix download)
   #:use-module (guix platform)
   #:use-module (guix build-system)
   #:use-module (guix build-system gnu)
@@ -45,7 +46,9 @@  (define-module (guix build-system cargo)
             crate-url
             crate-url?
             crate-uri
-            crate-name->package-name))
+            crate-name->package-name
+            crate-source
+            cargo-inputs))
 
 (define %crate-base-url
   (make-parameter "https://crates.io"))
@@ -62,6 +65,46 @@  (define (crate-uri name version)
 (define (crate-name->package-name name)
   (downstream-package-name "rust-" name))
 
+(define* (crate-source name version hash #:key (patches '()) (snippet #f))
+  (origin
+    (method url-fetch)
+    (uri (crate-uri name version))
+    (file-name
+     (string-append (crate-name->package-name name) "-" version ".tar.gz"))
+    (sha256 (base32 hash))
+    (modules '((guix build utils)))
+    (patches patches)
+    (snippet snippet)))
+
+(define* (cargo-inputs name #:key (crates-module '(gnu packages rust-crates))
+                       (sources-module '(gnu packages rust-sources)))
+  "Given NAME, resolve input list 'NAME-cargo-inputs' in CRATES-MODULE, return
+its copy with #f removed and symbols resolved to variables defined in
+SOURCES-MODULE, if the list exists, otherwise return an empty list."
+  (let loop ((inputs
+              (catch #t
+                (lambda ()
+                  (module-ref (resolve-interface crates-module)
+                              (symbol-append name '-cargo-inputs)))
+                (const '())))
+             (result '()))
+    (if (null? inputs)
+        result
+        (match inputs
+          ((input . rest)
+           (loop rest
+                 (cond
+                  ;; #f, remove it.
+                  ((not input)
+                   result)
+                  ;; Symbol, resolve it in SOURCES-MODULE.
+                  ((symbol? input)
+                   (cons (module-ref (resolve-interface sources-module) input)
+                         result))
+                  ;; Else: no change.
+                  (else
+                   (cons input result)))))))))
+
 (define (default-rust target)
   "Return the default Rust package."
   ;; Lazily resolve the binding to avoid a circular dependency.
diff --git a/guix/import/crate.scm b/guix/import/crate.scm
index 14e6e28c5b..a6f247bbae 100644
--- a/guix/import/crate.scm
+++ b/guix/import/crate.scm
@@ -27,7 +27,7 @@ 
 
 (define-module (guix import crate)
   #:use-module (guix base32)
-  #:use-module (guix build-system cargo)
+  #:use-module ((guix build-system cargo) #:hide (crate-source))
   #:use-module (guix diagnostics)
   #:use-module (gcrypt hash)
   #:use-module (guix http-client)