gnu: Add texlive-tabu.

* gnu/packages/tex.scm (texlive-tabu): New variable.

gnu/packages/tex.scm

@@ -8773,6 +8773,50 @@ LuaTeX (respectively) is not the engine in use.")
 
 (define-deprecated-package texlive-generic-ifxetex texlive-generic-iftex)
 
+(define-public texlive-tabu
+  (let ((template
+         (simple-texlive-package
+          "texlive-tabu"
+          (list "doc/latex/tabu/"
+                "source/latex/tabu/"
+                "tex/latex/tabu/")
+          (base32 "0mixyrqavipq4ni38z42x3579cdjbz54cp2qqb4q4yhfbl0a4pka"))))
+    (package
+      (inherit template)
+      (outputs '("out" "doc"))
+      (arguments
+       (substitute-keyword-arguments (package-arguments template)
+         ((#:tex-directory _ '())
+          "latex/tabu")
+         ((#:build-targets _ '())
+          '(list "tabu.dtx"))
+         ((#:phases phases)
+          `(modify-phases ,phases
+             (add-after 'unpack 'chdir
+               (lambda _ (chdir "source/latex/tabu")))
+             (replace 'copy-files
+               (lambda* (#:key inputs outputs #:allow-other-keys)
+                 (let ((origin (assoc-ref inputs "source"))
+                       (source (string-append (assoc-ref outputs "out")
+                                              "/share/texmf-dist/source"))
+                       (doc (string-append (assoc-ref outputs "doc")
+                                           "/share/texmf-dist/doc")))
+                   (copy-recursively (string-append origin "/source") source)
+                   (copy-recursively (string-append origin "/doc") doc))))))))
+      (propagated-inputs (list texlive-varwidth))
+      (home-page "https://ctan.org/macros/latex/contrib/tabu")
+      (synopsis "Flexible LaTeX tabulars")
+      (description
+       "The package provides an environment, tabu, which will make any sort of
+tabular, and an environment longtabu which provides the facilities of tabu in
+a modified longtable environment.  The package requires array, xcolor for
+coloured rules in tables, and colortbl for coloured cells.  The longtabu
+environment further requires that longtable be loaded.  The package itself
+does not load any of these packages for the user.  The tabu environment may be
+used in place of @code{tabular}, @code{tabular*} and @code{tabularx}
+environments, as well as the @code{array} environment in maths mode.")
+      (license license:lppl1.3+))))
+
 (define-public texlive-tools
   (let ((template (simple-texlive-package
                    "texlive-tools"