gnu: Use 'search-input-file' when looking for executables.

* gnu/packages/admin.scm (isc-dhcp): Use 'search-input-file' when
looking for executables.
* gnu/packages/audio.scm (ableton-link): Likewise.
* gnu/packages/benchmark.scm (fio): Likewise.
* gnu/packages/bioinformatics.scm (roary): Likewise.
(ngless): Likewise.
* gnu/packages/boost.scm (boost-for-irods): Likewise.
* gnu/packages/bootloaders.scm (grub): Likewise.
(grub-efi): Likewise.
* gnu/packages/chemistry.scm (inchi): Likewise.
* gnu/packages/dictionaries.scm (ding): Likewise.
* gnu/packages/dlang.scm (ldc): Likewise.
* gnu/packages/education.scm (childsplay): Likewise.
* gnu/packages/emacs-xyz.scm (emacs-hyperbole): Likewise.
(emacs-haskell-mode): Likewise.
(emacs-auctex): Likewise.
(emacs-ggtags): Likewise.
(emacs-graphviz-dot-mode): Likewise.
(emacs-flycheck-grammalecte): Likewise.
(emacs-counsel-notmuch): Likewise.
(emacspeak): Likewise.
(emacs-exwm): Likewise.
(emacs-exwm-x): Likewise.
(emacs-treemacs): Likewise.
(emacs-telega): Likewise.
(emacs-exiftool): Likewise.
* gnu/packages/emulators.scm (higan): Likewise.
* gnu/packages/engineering.scm (freehdl): Likewise.
(librepcb): Likewise.
* gnu/packages/entr.scm (entr): Likewise.
* gnu/packages/file-systems.scm (libeatmydata): Likewise.
(xfstests): Likewise.
(mergerfs): Likewise.
(mergerfs-tools): Likewise.
* gnu/packages/finance.scm (monero-gui): Likewise.
* gnu/packages/flashing-tools.scm (flashrom): Likewise.
* gnu/packages/fontutils.scm (fontforge): Likewise.
* gnu/packages/game-development.scm (python2-renpy): Likewise.
* gnu/packages/games.scm (opensurge): Likewise.
(xboard): Likewise.
(hyperrogue): Likewise.
(flare-game): Likewise.
(chessx): Likewise.
* gnu/packages/geo.scm (grass): Likewise.
* gnu/packages/glib.scm (glib): Likewise.
* gnu/packages/gnome.scm (mm-common): Likewise.
(network-manager-openvpn): Likewise.
(network-manager-vpnc): Likewise.
(network-manager-openconnect): Likewise.
(apostrophe): Likewise.
* gnu/packages/gnupg.scm (pius): Likewise.
(jetring): Likewise.
* gnu/packages/gnuzilla.scm (icedove): Likewise.
* gnu/packages/golang.scm (go-1.4): Likewise.
* gnu/packages/graphviz.scm (xdot): Likewise.
* gnu/packages/guile-xyz.scm (jupyter-guile-kernel): Likewise.
* gnu/packages/haskell-xyz.scm (ghc-hindent): Likewise.
* gnu/packages/ibus.scm (ibus): Likewise.
* gnu/packages/image.scm (phockup): Likewise.
* gnu/packages/irc.scm (quassel): Likewise.
* gnu/packages/java.scm (drip): Likewise.
(ant-bootstrap): Likewise.
(tla2tools): Likewise.
* gnu/packages/julia.scm (julia): Likewise.
* gnu/packages/less.scm (lesspipe): Likewise.
* gnu/packages/libreoffice.scm (libreoffice): Likewise.
* gnu/packages/linux.scm (fuse): Likewise.
(lm-sensors): Likewise.
(bluez): Likewise.
(fakeroot): Likewise.
(inputattach): Likewise.
* gnu/packages/lisp-xyz.scm (sbcl-cl-diskspace): Likewise.
* gnu/packages/lisp.scm (lisp-repl-core-dumper): Likewise.
* gnu/packages/lua.scm (fennel): Likewise.
* gnu/packages/lxde.scm (spacefm): Likewise.
* gnu/packages/mail.scm (public-inbox): Likewise.
* gnu/packages/maths.scm (hdf-java): Likewise.
(maxima): Likewise.
(frama-c): Likewise.
* gnu/packages/messaging.scm (libgadu): Likewise.
* gnu/packages/music.scm (denemo): Likewise.
(curseradio): Likewise.
* gnu/packages/netpbm.scm (netpbm): Likewise.
* gnu/packages/networking.scm (blueman): Likewise.
(squid): Likewise.
(aircrack-ng): Likewise.
* gnu/packages/node.scm (node): Likewise.
(node-llparse-frontend-bootstrap): Likewise.
(node-llparse-bootstrap): Likewise.
(llhttp-bootstrap): Likewise.
(node-lts): Likewise.
* gnu/packages/ocaml.scm (ocaml-4.11): Likewise.
(opam): Likewise.
(ocaml-graph): Likewise.
* gnu/packages/orpheus.scm (orpheus): Likewise.
* gnu/packages/password-utils.scm (password-store): Likewise.
* gnu/packages/python.scm (pypy3): Likewise.
* gnu/packages/qt.scm (qt5ct): Likewise.
* gnu/packages/radio.scm (libosmo-dsp): Likewise.
* gnu/packages/ruby.scm (ruby-pandoc-ruby): Likewise.
* gnu/packages/rust.scm (rust-1.30): Likewise.
* gnu/packages/screen.scm (byobu): Likewise.
* gnu/packages/statistics.scm (r-with-tests): Likewise.
* gnu/packages/suckless.scm (surf): Likewise.
* gnu/packages/syndication.scm (gfeeds): Likewise.
* gnu/packages/telephony.scm (mumble): Likewise.
* gnu/packages/terminals.scm (alacritty): Likewise.
* gnu/packages/tex.scm (texlive-bin): Likewise.
* gnu/packages/uml.scm (plantuml): Likewise.
* gnu/packages/version-control.scm (python-git-multimail): Likewise.
(gitolite): Likewise.
(hg-commitsigs): Likewise.
(git-when-merged): Likewise.
(git-imerge): Likewise.
(gita): Likewise.
* gnu/packages/video.scm (you-get): Likewise.
* gnu/packages/vim.scm (eovim): Likewise.
* gnu/packages/virtualization.scm (qemu): Likewise.
(virt-manager): Likewise.
(criu): Likewise.
* gnu/packages/vpn.scm (strongswan): Likewise.
(xl2tpd): Likewise.
* gnu/packages/wm.scm (i3lock-fancy): Likewise.
* gnu/packages/wxwidgets.scm (python-wxpython): Likewise.
(python2-wxpython): Likewise.
* gnu/packages/xdisorg.scm (autorandr): Likewise.
* gnu/packages/xorg.scm (hackneyed-x11-cursors): Likewise.
(v86d): Likewise.
(mkfontdir): Likewise.
(xpra): Likewise.

gnu/packages/emacs-xyz.scm

@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2014 Taylan Ulrich Bayirli/Kammer <taylanbayirli@gmail.com>
-;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2014, 2015, 2016, 2017, 2018 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2019 Alex Kost <alezost@gmail.com>
 ;;; Copyright © 2015 Federico Beffa <beffa@fbengineering.ch>
@@ -484,8 +484,7 @@ system.")
            (lambda* (#:key inputs #:allow-other-keys)
              (substitute* "hypb.el"
                (("/bin/domainname")
-                (string-append (assoc-ref inputs "inetutils")
-                               "/bin/dnsdomainname")))
+                (search-input-file inputs "bin/dnsdomainname")))
              (substitute* "hyperbole.el"
                (("\\(hyperb:check-dir-user\\)") ""))))
          (add-after 'install 'install-images
@@ -1413,7 +1412,7 @@ replacement.")
                  ((f1 f2 ...) (dirname f1))
                  (_ "")))
 
-             (let ((sh (string-append (assoc-ref inputs "bash") "/bin/sh")))
+             (let ((sh (search-input-file inputs "/bin/sh")))
                (define emacs-prefix? (cut string-prefix? "emacs-" <>))
 
                (setenv "SHELL" "sh")
@@ -2568,7 +2567,7 @@ as a library for other Emacs packages.")
            (lambda* (#:key inputs #:allow-other-keys)
              (emacs-substitute-variables "preview.el"
                ("preview-gs-command"
-                (string-append (assoc-ref inputs "ghostscript") "/bin/gs")))
+                (search-input-file inputs "/bin/gs")))
              (substitute* "preview.el"
                (("\"dvipng ")
                 (string-append "\"" (assoc-ref inputs "texlive")
@@ -2932,8 +2931,7 @@ into mode hooks and is intended to be used that way.")
              (chmod "ggtags.el" #o644)
              (emacs-substitute-variables "ggtags.el"
                ("ggtags-executable-directory"
-                (string-append (assoc-ref inputs "global") "/bin")))
-             #t)))))
+                (dirname (search-input-file inputs "bin/global")))))))))
     (home-page "https://github.com/leoliu/ggtags")
     (synopsis "Frontend to the GNU Global source code tagging system")
     (description "@code{ggtags} provides a frontend to the GNU Global source
@@ -3039,7 +3037,7 @@ directly inside Emacs.  It requires a Google Map Static API key to function.")
              (with-directory-excursion "texinfo"
                (substitute* "Makefile"
                  (("\\/usr\\/bin\\/gzip")
-                  (string-append (assoc-ref inputs "gzip") "/bin/gzip")))
+                  (search-input-file inputs "/bin/gzip")))
                (invoke "make"
                        "clean"
                        "info"
@@ -5503,8 +5501,7 @@ for Flow files.")
          (add-after 'unpack 'specify-python-location
            ;; Hard-code python3 executable location in the library.
            (lambda* (#:key inputs #:allow-other-keys)
-             (let ((python3 (string-append (assoc-ref inputs "python")
-                                           "/bin/python3")))
+             (let ((python3 (search-input-file inputs "/bin/python3")))
                (substitute* "flycheck-grammalecte.el"
                  (("\"python3") (string-append "\"" python3)))
                (substitute* '("conjugueur.py" "flycheck-grammalecte.py")
@@ -9276,9 +9273,7 @@ queries using counsel.")
                (make-file-writable "counsel-notmuch.el")
                (emacs-substitute-variables "counsel-notmuch.el"
                  ("counsel-notmuch-path"
-                  (string-append (assoc-ref inputs "notmuch")
-                                 "/bin/notmuch")))
-               #t)))))
+                  (search-input-file inputs "/bin/notmuch"))))))))
       (inputs
        `(("emacs-counsel" ,emacs-counsel)
          ("notmuch" ,notmuch)
@@ -12973,8 +12968,7 @@ highlights quasi-quoted expressions.")
                     (bin (string-append out "/bin"))
                     (lisp (string-append out "/share/emacs/site-lisp/emacspeak"))
                     (info (string-append out "/share/info"))
-                    (emacs (string-append (assoc-ref inputs "emacs")
-                                          "/bin/emacs")))
+                    (emacs (search-input-file inputs "/bin/emacs")))
                ;; According to etc/install.org, the Emacspeak directory should
                ;; be copied to its installation destination.
                (for-each
@@ -13700,10 +13694,10 @@ It should enable you to implement low-level X11 applications.")
                    (format #t "#!~a ~@
                      ~a +SI:localuser:$USER ~@
                      exec ~a --exit-with-session ~a \"$@\" --eval '~s' ~%"
-                           (string-append (assoc-ref inputs "bash") "/bin/sh")
-                           (string-append (assoc-ref inputs "xhost") "/bin/xhost")
-                           (string-append (assoc-ref inputs "dbus") "/bin/dbus-launch")
-                           (string-append (assoc-ref inputs "emacs") "/bin/emacs")
+                           (search-input-file inputs "/bin/sh")
+                           (search-input-file inputs "/bin/xhost")
+                           (search-input-file inputs "/bin/dbus-launch")
+                           (search-input-file inputs "/bin/emacs")
                            '(cond
                              ((file-exists-p "~/.exwm")
                               (load-file "~/.exwm"))
@@ -13816,10 +13810,10 @@ other operations.")
                    (format #t "#!~a ~@
                      ~a +SI:localuser:$USER ~@
                      exec ~a --exit-with-session ~a \"$@\" --eval '~s' ~%"
-                           (string-append (assoc-ref inputs "bash") "/bin/sh")
-                           (string-append (assoc-ref inputs "xhost") "/bin/xhost")
-                           (string-append (assoc-ref inputs "dbus") "/bin/dbus-launch")
-                           (string-append (assoc-ref inputs "emacs") "/bin/emacs")
+                           (search-input-file inputs "/bin/sh")
+                           (search-input-file inputs "/bin/xhost")
+                           (search-input-file inputs "/bin/dbus-launch")
+                           (search-input-file inputs "/bin/emacs")
                            '(require 'exwmx-loader))))
                (chmod exwm-executable #o555)
                #t))))))
@@ -23332,7 +23326,7 @@ processes for Emacs")
                (chmod "src/elisp/treemacs-customization.el" #o644)
                (emacs-substitute-variables "src/elisp/treemacs-customization.el"
                  ("treemacs-python-executable"
-                  (string-append (assoc-ref inputs "python") "/bin/python3")))
+                  (search-input-file inputs "/bin/python3")))
                (chmod "src/elisp/treemacs-async.el" #o644)
                (substitute* "src/elisp/treemacs-async.el"
                  (("src/scripts") (string-append "share/" ,name "/scripts"))))
@@ -26285,14 +26279,14 @@ service, and connect it with Emacs via inter-process communication.")
          (add-after 'unpack 'patch-sources
            (lambda* (#:key inputs #:allow-other-keys)
              ;; Hard-code paths to `ffplay` and `ffmpeg`.
-             (let* ((ffmpeg (assoc-ref inputs "ffmpeg"))
-                    (ffmpeg-bin (string-append ffmpeg "/bin/ffmpeg"))
-                    (ffplay-bin (string-append ffmpeg "/bin/ffplay")))
+             (let* ((ffplay-bin (search-input-file inputs "/bin/ffplay"))
+                    (ffmpeg-bin (search-input-file inputs "/bin/ffmpeg")))
                (substitute* '("telega-ffplay.el" "telega-vvnote.el")
                  (("(shell-command-to-string\|concat) \"(ffmpeg\|ffprobe)"
                    all func cmd)
-                  (string-append func " \"" (assoc-ref inputs "ffmpeg")
-                                 "/bin/" cmd))
+                  (string-append func " \""
+                                 (search-input-file
+                                  inputs (string-append "/bin/" cmd))))
                  (("\\(executable-find \"ffplay\"\\)")
                   (string-append "(and (file-executable-p \"" ffplay-bin "\")"
                                  "\"" ffplay-bin "\")"))
@@ -26303,8 +26297,7 @@ service, and connect it with Emacs via inter-process communication.")
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (substitute* "telega-server.el"
                (("@TELEGA_SERVER_BIN@")
-                (string-append (assoc-ref inputs "emacs-telega-server")
-                               "/bin/telega-server")))
+                (search-input-file inputs "/bin/telega-server")))
              (substitute* "telega-util.el"
                (("@TELEGA_SHARE@")
                 (string-append (assoc-ref outputs "out")
@@ -27596,9 +27589,7 @@ emoji.")
              (make-file-writable "exiftool.el")
              (emacs-substitute-variables "exiftool.el"
                ("exiftool-executable"
-                (string-append (assoc-ref inputs "perl-image-exiftool")
-                               "/bin/exiftool")))
-             #t)))))
+                (search-input-file inputs "/bin/exiftool"))))))))
     (inputs
      `(("perl-image-exiftool" ,perl-image-exiftool)))
     (home-page "https://git.systemreboot.net/exiftool.el/about/")