gnu: commencement: Use locales for the right libc version on GNU/Hurd.

Fixes <https://issues.guix.gnu.org/66472>.

Until now, we were unconditionally using ‘glibc-utf8-locales’, which
targets the glibc version used on Linux (2.35) rather than that used on
the Hurd (2.37).  This would lead to build failures due to the inability
to use locale encoding when targeting i586-gnu.

* gnu/packages/base.scm (glibc-utf8-locales/hurd): New variable.
* gnu/packages/commencement.scm (glibc-utf8-locales-final/hurd): New
variable.
(%boot5-inputs): Use it when ‘target-hurd?’ returns #t.
(%final-inputs): Likewise.

Change-Id: I1666d615dffbe3561cf2d9612b85cd31a48a7dcd

gnu/packages/base.scm

@@ -1512,6 +1512,11 @@ command.")
            (delete 'build)))))                  ; nothing to build
     (supported-systems %hurd-systems)))
 
+(define-public glibc-utf8-locales/hurd
+  ;; Locales for the libc version used on GNU/Hurd.
+  (hidden-package
+   (make-glibc-utf8-locales glibc/hurd)))
+
 (define* (libc-for-target #:optional
                           (target (or (%current-target-system)
                                       (%current-system))))

gnu/packages/commencement.scm

@@ -3365,6 +3365,16 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
      `(("glibc" ,glibc-final)
        ("gzip" ,(with-boot4 gzip))))))
 
+(define-public glibc-utf8-locales-final/hurd
+  ;; Locales for the libc version used on GNU/Hurd.
+  (package
+    (inherit glibc-utf8-locales/hurd)
+    (properties `((hidden? . #t)
+                  ,@(package-properties glibc-utf8-locales/hurd)))
+    (native-inputs
+     `(("glibc" ,glibc-final)
+       ("gzip" ,(with-boot4 gzip))))))
+
 (define-public ld-wrapper
   ;; The final 'ld' wrapper, which uses the final Guile and Binutils.
   (make-ld-wrapper "ld-wrapper"
@@ -3383,7 +3393,9 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
   ;; Now with UTF-8 locales.  Remember that the bootstrap binaries were built
   ;; with an older libc, which cannot load the new locale format.  See
   ;; <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
-  `(("locales" ,glibc-utf8-locales-final)
+  `(("locales" ,(if (target-hurd?)
+                    glibc-utf8-locales-final/hurd
+                    glibc-utf8-locales-final))
     ,@(%boot4-inputs)))
 
 (define with-boot5
@@ -3484,7 +3496,9 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
           ("gcc" ,gcc-final)
           ("libc" ,glibc-final)
           ("libc:static" ,glibc-final "static")
-          ("locales" ,glibc-utf8-locales-final))))))
+          ("locales" ,(if (target-hurd?)
+                          glibc-utf8-locales-final/hurd
+                          glibc-utf8-locales-final)))))))
 
 (define-public canonical-package
   (let ((name->package (mlambda (system)