gnu: Add texlive-firstaid.

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

gnu/packages/tex.scm

@@ -5063,6 +5063,44 @@ corresponding italics: light, regular, medium, bold, ...")
     (license (list license:lppl
                    license:silofl1.1))))
 
+(define-public texlive-firstaid
+  (let ((template (simple-texlive-package
+                   "texlive-firstaid"
+                   (list "/doc/latex/firstaid/"
+                         "/source/latex/firstaid/"
+                         "/tex/latex/firstaid/")
+                   (base32
+                    "1ahn47kz8a2qdmzdfdgjanf6h5bn8f2rzp1zvwgjpk1plcix8k90"))))
+    (package
+      (inherit template)
+      (arguments
+       (substitute-keyword-arguments (package-arguments template)
+         ((#:tex-directory _ #t) "tex/latex/firstaid")
+         ((#:build-targets _ '()) '(list "firstaid.ins"))
+         ((#:phases phases)
+          #~(modify-phases #$phases
+              (add-after 'unpack 'chdir
+                (lambda _ (chdir "source/latex/firstaid/")))
+              (replace 'copy-files
+                (lambda* (#:key inputs #:allow-other-keys)
+                  (let ((origin (assoc-ref inputs "source"))
+                        (source (string-append #$output
+                                               "/share/texmf-dist/source"))
+                        (doc (string-append #$output:doc
+                                            "/share/texmf-dist/doc")))
+                    (copy-recursively (string-append origin "/source") source)
+                    (copy-recursively (string-append origin "/doc") doc))))))))
+      (home-page "https://ctan.org/macros/latex/required/firstaid")
+      (synopsis
+       "First aid for external LaTeX files and packages that need updating")
+      (description
+       "This package contains some first aid for LaTeX packages or classes
+that require updates because of internal changes to the LaTeX kernel that are
+not yet reflected in the package's or class's code.  The file
+@file{latex2e-first-aid-for-external-files.ltx} provided by this package is
+meant to be loaded during format generation and not by the user.")
+      (license license:lppl1.3c))))
+
 (define-public texlive-latex-ifplatform
   (package
     (name "texlive-latex-ifplatform")