libkml: make boost a :build and :test dep

ZhongRuoyu · ZhongRuoyu · commit be12de1518bc · 2023-04-12T14:46:42.000+08:00
See discussions in Homebrew#128083.
diff --git a/Formula/libkml.rb b/Formula/libkml.rb
@@ -16,10 +16,10 @@ class Libkml < Formula
     sha256 cellar: :any_skip_relocation, x86_64_linux:   "81a8cdd08aa6620f894eae9b3bd37184bb08f25800aba660c234320e4b51ef75"
   end
 
+  depends_on "boost" => [:build, :test]
   depends_on "cmake" => :build
   depends_on "googletest" => :test
   depends_on "pkg-config" => :test
-  depends_on "boost"
   depends_on "minizip"
   depends_on "uriparser"
 
@@ -32,6 +32,12 @@ def install
     system "cmake", "--install", "build"
   end
 
+  def caveats
+    <<~EOS
+      libkml uses boost headers. To develop with libkml, install boost.
+    EOS
+  end
+
   test do
     (testpath/"test.cpp").write <<~EOS
       #include "kml/regionator/regionator_qid.h"
