gz-math7: patch to build multiple python bindings (#2840)

* Build bindings for both [email protected] and [email protected].
* revision bump
* update  bottle.

Signed-off-by: Steve Peters <[email protected]>
Co-authored-by: OSRF Build Bot <[email protected]>

Formula/gz-math7.rb

@@ -4,43 +4,72 @@ class GzMath7 < Formula
   url "https://osrf-distributions.s3.amazonaws.com/gz-math/releases/gz-math-7.5.1.tar.bz2"
   sha256 "cb1fc3436fd57ff9663613576fc208018ed6c11776972e555400d1b8bb7d2426"
   license "Apache-2.0"
+  revision 1
 
   head "https://github.com/gazebosim/gz-math.git", branch: "gz-math7"
 
   bottle do
     root_url "https://osrf-distributions.s3.amazonaws.com/bottles-simulation"
-    sha256 cellar: :any, sonoma:   "8ce91642ee2f4bdc18be0a63b758a7d634a200eebc95cd4a4e20a0940c5202b3"
-    sha256 cellar: :any, ventura:  "faef596eaa7c1686fca3bcfa3ff0595d21128b480dd70ff66cef4fb542c3de0e"
-    sha256 cellar: :any, monterey: "30ff425a806ecc8894772834cc3a7ef07cb5c6808c48504fee7876d9dc2ca13b"
+    sha256 cellar: :any, sonoma:  "fc68e0969e29460070b13ce4cbb49e53c9802821267ef6aad64e55bffca068ec"
+    sha256 cellar: :any, ventura: "1d95728e7a681a67aa0ac9899e9bcc1e7ca0f03835ba4c79f3e17eaa0b26d0a7"
   end
 
   depends_on "cmake" => :build
   depends_on "doxygen" => :build
   depends_on "pybind11" => :build
+  depends_on "[email protected]" => [:build, :test]
+  depends_on "[email protected]" => [:build, :test]
+  depends_on "pkg-config" => :test
   depends_on "eigen"
   depends_on "gz-cmake3"
   depends_on "gz-utils2"
-  depends_on "[email protected]"
   depends_on "ruby"
 
-  def python_cmake_arg
-    "-DPython3_EXECUTABLE=#{which("python3")}"
+  patch do
+    # Support building python bindings against external gz-math library (1)
+    # Remove this patch with the next release
+    url "https://github.com/gazebosim/gz-math/commit/97ad436a0d561c77422de83cebb600379cc9c94a.patch?full_index=1"
+    sha256 "6d2ed400c7067ac123c80d762f796d2b75e3b4ab479ee71b019e253ca41724e8"
+  end
+
+  patch do
+    # Support building python bindings against external gz-math library (2)
+    # Remove this patch with the next release
+    url "https://github.com/gazebosim/gz-math/commit/a48b8937eadd4010a69b9f9613ca07aaa1f87d63.patch?full_index=1"
+    sha256 "fbd10f7b886511586ab84c7c03771a43da2fbb5c9445037a6534bbdbd2d05062"
+  end
+
+  def pythons
+    deps.map(&:to_formula)
+        .select { |f| f.name.match?(/^python@3\.\d+$/) }
+  end
+
+  def python_cmake_arg(python = "[email protected]".to_formula)
+    "-DPython3_EXECUTABLE=#{python.opt_libexec}/bin/python"
   end
 
   def install
     cmake_args = std_cmake_args
     cmake_args << "-DBUILD_TESTING=OFF"
     cmake_args << "-DCMAKE_INSTALL_RPATH=#{rpath}"
-    cmake_args << python_cmake_arg
 
-    # Use a build folder
+    # first build without python bindings
     mkdir "build" do
-      system "cmake", "..", *cmake_args
+      system "cmake", "..", *cmake_args, "-DSKIP_PYBIND11=ON"
       system "make", "install"
     end
 
-    (lib/"python3.12/site-packages").install Dir[lib/"python/*"]
-    rmdir prefix/"lib/python"
+    # now build only the python bindings
+    pythons.each do |python|
+      # remove @ from formula name
+      python_name = python.name.tr("@", "")
+      mkdir "build_#{python_name}" do
+        system "cmake", "../src/python_pybind11", *cmake_args, python_cmake_arg(python)
+        system "make", "install"
+        (lib/"#{python_name}/site-packages").install Dir[lib/"python/*"]
+        rmdir prefix/"lib/python"
+      end
+    end
   end
 
   test do
@@ -59,12 +88,12 @@ def install
       add_executable(test_cmake test.cpp)
       target_link_libraries(test_cmake gz-math7::gz-math7)
     EOS
-    # test building with manual compiler flags
+    system "pkg-config", "gz-math7"
+    cflags = `pkg-config --cflags gz-math7`.split
+    ldflags = `pkg-config --libs gz-math7`.split
     system ENV.cc, "test.cpp",
-                   "--std=c++14",
-                   "-I#{include}/gz/math7",
-                   "-L#{lib}",
-                   "-lgz-math7",
+                   *cflags,
+                   *ldflags,
                    "-lc++",
                    "-o", "test"
     system "./test"
@@ -78,6 +107,8 @@ def install
     cmd_not_grep_xcode = "! grep -rnI 'Applications[/]Xcode' #{prefix}"
     system cmd_not_grep_xcode
     # check python import
-    system Formula["[email protected]"].opt_libexec/"bin/python", "-c", "import gz.math7"
+    pythons.each do |python|
+      system python.opt_libexec/"bin/python", "-c", "import gz.math7"
+    end
   end
 end