plowshare: add caveat about X11 support for imagemagick

Closes #15550.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/Library/Formula/plowshare.rb b/Library/Formula/plowshare.rb
index 725c9baa2..b5ae47abd 100644
--- a/Library/Formula/plowshare.rb
+++ b/Library/Formula/plowshare.rb
@@ -24,6 +24,15 @@ class Plowshare < Formula
     ENV["PREFIX"] = prefix
     system "bash setup.sh install"
   end
+
+  def caveats; <<-EOS.undent
+    The default installation of imagemagick does not enable
+    X11 support. plowshare uses the display command which does
+    not work if X11 support is not enabled. To enable:
+      brew remove imagemagick
+      brew install imagemagick --with-x
+    EOS
+  end
 end