build: check-final-inputs-self-contained has an exception for 'bash:include'.

Currently 'bash:include' of the final Bash depends on bootstrap stuff.

* build-aux/check-final-inputs-self-contained.scm (final-inputs): Add
clause for 'bash:include'.
* gnu/packages/commencement.scm (bash-final): Add FIXME comment.

build-aux/check-final-inputs-self-contained.scm

@@ -37,12 +37,17 @@
                 (let ((drv (package-derivation store package system)))
                   ;; Libc's 'debug' output refers to gcc-cross-boot0, but it's
                   ;; hard to avoid, so we tolerate it.  This should be the
-                  ;; only exception.
+                  ;; only exception.  Likewise, 'bash:include' depends on
+                  ;; bootstrap-binaries via its 'Makefile.inc' (FIXME).
                   (filter-map (match-lambda
                                (("debug" . directory)
                                 (if (string=? "glibc" (package-name package))
                                     #f
                                     directory))
+                               (("include" . directory)
+                                (if (string=? "bash" (package-name package))
+                                    #f
+                                    directory))
                                ((_ . directory) directory))
                               (derivation->output-paths drv)))))
               %final-inputs))

gnu/packages/commencement.scm

@@ -783,6 +783,7 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
 (define bash-final
   ;; Link with `-static-libgcc' to make sure we don't retain a reference
   ;; to the bootstrap GCC.
+  ;; FIXME: This depends on 'bootstrap-binaries' via Makefile.in.
   (package-with-bootstrap-guile
    (package-with-explicit-inputs (static-libgcc-package bash)
                                  %boot3-inputs