gnu: youtube-viewer: Add missing comment.

This is a follow-up to 315b98b9eb71e1a56de6a49ffbfed0af3c92be7e.

* gnu/packages/video.scm (youtube-viewer)[arguments]: Add comment
explaining why we don't install the gtk3 variant.

diff --git a/gnu/packages/video.scm b/gnu/packages/video.scm
index 2ca8605..227c11d 100644 (file)
--- a/gnu/packages/video.scm
+++ b/gnu/packages/video.scm
@@ -1860,6 +1860,8 @@ audio, images) from the Web.  It can use either mpv or vlc for playback.")
      `(#:modules ((guix build perl-build-system)
                   (guix build utils)
                   (srfi srfi-26))
+       ;; gtk-2/3 variants are both installed by default but the gtk3 variant
+       ;; is broken without perl-gtk3.
        #:module-build-flags '("--gtk2")
        #:phases
        (modify-phases %standard-phases