gnu: fbcat: Update to 0.5.1.

* gnu/packages/linux.scm (fbcat): Update to 0.5.1.
[native-inputs]: Remove field.
[arguments]: Add PREFIX to #:make-flags.  Remove `fix-docbook-location'
and `build-documentation' phases.  Let the Makefile install everything.
Add a `split-fbgrab-output' to clean up.

gnu/packages/linux.scm

@@ -4551,20 +4551,15 @@ relevant @file{/dev/vcs*} file(s).")
 (define-public fbcat
   (package
     (name "fbcat")
-    (version "0.5")
+    (version "0.5.1")
     (source
      (origin
        (method url-fetch)
        (uri (string-append "https://github.com/jwilk/fbcat/releases/download/"
                            version "/" name "-" version ".tar.gz"))
        (sha256
-        (base32 "1dla1na3nf3s4xy0p6w0v54zipg1x8c14yqsw8w9qjzhchr4caxw"))))
+        (base32 "0pj9hxmwhbz6kmd7847yx2jh1scl9l25zgndyi8s9vlzdkq2q8d7"))))
     (build-system gnu-build-system)
-    (native-inputs
-     ;; For building the man pages.
-     `(("docbook-xml" ,docbook-xml)
-       ("docbook-xsl" ,docbook-xsl)
-       ("xsltproc" ,libxslt)))
     (inputs
      ;; The ‘fbgrab’ wrapper can use one of several PPM-to-PNG converters.  We
      ;; choose netpbm simply because it's the smallest.  It still adds ~94 MiB
@@ -4572,24 +4567,13 @@ relevant @file{/dev/vcs*} file(s).")
      `(("pnmtopng" ,netpbm)))
     (outputs (list "out" "fbgrab"))
     (arguments
-     `(#:make-flags (list "CC=gcc")
+     `(#:make-flags
+       (list "CC=gcc"
+             (string-append "PREFIX=" (assoc-ref %outputs "out")))
        #:tests? #f                      ; no tests
        #:phases
        (modify-phases %standard-phases
-         (add-after 'unpack 'fix-docbook-location
-           (lambda* (#:key inputs #:allow-other-keys)
-             (substitute* "doc/Makefile"
-               (("http://docbook.sourceforge.net/release/xsl/current")
-                (string-append (assoc-ref inputs "docbook-xsl")
-                               "/xml/xsl/docbook-xsl-"
-                               ,(package-version docbook-xsl))))
-             #t))
          (delete 'configure)            ; no configure script
-         (add-after 'build 'build-documentation
-           (lambda* (#:key make-flags #:allow-other-keys)
-             (apply invoke "make" "-C" "doc"
-                    make-flags)
-             #t))
          (add-after 'build 'qualify-references
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let* ((pnmtopng (assoc-ref inputs "pnmtopng"))
@@ -4600,17 +4584,17 @@ relevant @file{/dev/vcs*} file(s).")
                  (("pnmtopng" all)
                   (string-append pnmtopng "/bin/" all)))
                #t)))
-         (replace 'install
-           ;; The Makefile lacks an ‘install’ target.  Install files manually.
+         (add-after 'install 'split-fbgrab-output
            (lambda* (#:key outputs #:allow-other-keys)
              (let* ((out (assoc-ref outputs "out"))
                     (out:fbgrab (assoc-ref outputs "fbgrab")))
-               (install-file "fbcat" (string-append out "/bin"))
-               (install-file "doc/fbcat.1"
-                             (string-append out "/share/man/man1"))
-               (install-file "fbgrab" (string-append out:fbgrab "/bin"))
-               (install-file "doc/fbgrab.1"
-                             (string-append out:fbgrab "/share/man/man1"))
+               (for-each (lambda (file)
+                           (let ((old (string-append out "/" file))
+                                 (new (string-append out:fbgrab "/" file)))
+                             (mkdir-p (dirname new))
+                             (rename-file old new)))
+                         (list "bin/fbgrab"
+                               "share/man/man1/fbgrab.1"))
                #t))))))
     (home-page "https://jwilk.net/software/fbcat")
     (synopsis "Take a screenshot of the contents of the Linux framebuffer")