import: crate: Parameterized importing of dev dependencies.

The recursive crate importer will now include development dependencies only
for the top level package, but not for any of the recursively imported
packages.  Also #:skip-build will be false for the top-most package.

* guix/import/crate.scm (make-crate-sexp): Add the key BUILD?.
  (crate->guix-package): Add the key INCLUDE-DEV-DEPS?.
  (crate-recursive-import): Likewise.
* guix/scripts/import/crate.scm (guix-import-crate): Likewise.
* tests/crate.scm (cargo-recursive-import): Likewise.

guix/import/crate.scm

@@ -151,7 +151,7 @@ (define (maybe-arguments arguments)
      `((arguments (,'quasiquote ,args))))))
 
 (define* (make-crate-sexp #:key name version cargo-inputs cargo-development-inputs
-                          home-page synopsis description license)
+                          home-page synopsis description license build?)
   "Return the `package' s-expression for a rust package with the given NAME,
 VERSION, CARGO-INPUTS, CARGO-DEVELOPMENT-INPUTS, HOME-PAGE, SYNOPSIS, DESCRIPTION,
 and LICENSE."
@@ -177,7 +177,9 @@ (define (format-inputs inputs)
                               (base32
                                ,(bytevector->nix-base32-string (port-sha256 port))))))
                    (build-system cargo-build-system)
-                   ,@(maybe-arguments (append '(#:skip-build? #t)
+                   ,@(maybe-arguments (append (if build?
+                                                 '()
+                                                 '(#:skip-build? #t))
                                               (maybe-cargo-inputs cargo-inputs)
                                               (maybe-cargo-development-inputs
                                                 cargo-development-inputs)))
@@ -202,12 +204,13 @@ (define (string->license string)
                          'unknown-license!)))
               (string-split string (string->char-set " /"))))
 
-(define* (crate->guix-package crate-name #:key version repo)
+(define* (crate->guix-package crate-name #:key version include-dev-deps? repo)
   "Fetch the metadata for CRATE-NAME from crates.io, and return the
 `package' s-expression corresponding to that package, or #f on failure.
 When VERSION is specified, convert it into a semver range and attempt to fetch
 the latest version matching this semver range; otherwise fetch the latest
-version of CRATE-NAME."
+version of CRATE-NAME. If INCLUDE-DEV-DEPS is true then this will also
+look up the development dependencs for the given crate."
 
   (define (semver-range-contains-string? range version)
     (semver-range-contains? (string->semver-range range)
@@ -263,9 +266,12 @@ (define (sort-map-dependencies deps)
        (let* ((dependencies (crate-version-dependencies version*))
               (dep-crates dev-dep-crates (partition normal-dependency? dependencies))
               (cargo-inputs (sort-map-dependencies dep-crates))
-              (cargo-development-inputs '()))
+              (cargo-development-inputs (if include-dev-deps?
+                                            (sort-map-dependencies dev-dep-crates)
+                                            '())))
          (values
-          (make-crate-sexp #:name crate-name
+          (make-crate-sexp #:build? include-dev-deps?
+                           #:name crate-name
                            #:version (crate-version-number version*)
                            #:cargo-inputs cargo-inputs
                            #:cargo-development-inputs cargo-development-inputs
@@ -279,7 +285,12 @@ (define (sort-map-dependencies deps)
 
 (define* (crate-recursive-import crate-name #:key version)
   (recursive-import crate-name
-                    #:repo->guix-package (memoize crate->guix-package)
+                    #:repo->guix-package (lambda* params
+                      ;; download development dependencies only for the top level package
+                      (let ((include-dev-deps? (equal? (car params) crate-name))
+                            (crate->guix-package* (memoize crate->guix-package)))
+                        (apply crate->guix-package*
+                               (append params `(#:include-dev-deps? ,include-dev-deps?)))))
                     #:version version
                     #:guix-name crate-name->package-name))
 

guix/scripts/import/crate.scm

@@ -96,7 +96,7 @@ (define-values (name version)
 
        (if (assoc-ref opts 'recursive)
            (crate-recursive-import name #:version version)
-           (let ((sexp (crate->guix-package name #:version version)))
+           (let ((sexp (crate->guix-package name #:version version #:include-dev-deps? #t)))
              (unless sexp
                (leave (G_ "failed to download meta-data for package '~a'~%")
                       (if version

tests/crate.scm

@@ -536,8 +536,7 @@ (define-public 'rust-root-1.0.4
                      (?  string? hash)))))
                 (build-system cargo-build-system)
                 (arguments
-                 ('quasiquote (#:skip-build? #t
-                               #:cargo-inputs
+                 ('quasiquote (#:cargo-inputs
                                (("rust-intermediate-a"
                                  ('unquote 'rust-intermediate-a-1.0.42))
                                 ("rust-intermediate-b"