cython: revision bump for [email protected]

Formula/cython.rb

@@ -3,6 +3,7 @@ class Cython < Formula
   homepage "https://cython.org/"
   url "https://files.pythonhosted.org/packages/49/8a/6a4135469372da2e3d9f88f71c6d00d8a07ef65f121eeca0c7ae21697219/Cython-0.29.16.tar.gz"
   sha256 "232755284f942cbb3b43a06cd85974ef3c970a021aef19b5243c03ee2b08fa05"
+  revision 1
 
   bottle do
     cellar :any_skip_relocation
@@ -16,19 +17,19 @@ class Cython < Formula
     Users are advised to use `pip` to install cython
   EOS
 
-  depends_on "python"
+  depends_on "python@3.8"
 
   def install
-    xy = Language::Python.major_minor_version "python3"
+    xy = Language::Python.major_minor_version Formula["[email protected]"].opt_bin/"python3"
     ENV.prepend_create_path "PYTHONPATH", libexec/"lib/python#{xy}/site-packages"
-    system "python3", *Language::Python.setup_install_args(libexec)
+    system Formula["[email protected]"].opt_bin/"python3", *Language::Python.setup_install_args(libexec)
 
     bin.install Dir[libexec/"bin/*"]
     bin.env_script_all_files(libexec/"bin", :PYTHONPATH => ENV["PYTHONPATH"])
   end
 
   test do
-    xy = Language::Python.major_minor_version "python3"
+    xy = Language::Python.major_minor_version Formula["[email protected]"].opt_bin/"python3"
     ENV.prepend_path "PYTHONPATH", libexec/"lib/python#{xy}/site-packages"
 
     phrase = "You are using Homebrew"
@@ -41,7 +42,7 @@ def install
         ext_modules = cythonize("package_manager.pyx")
       )
     EOS
-    system "python3", "setup.py", "build_ext", "--inplace"
-    assert_match phrase, shell_output("python3 -c 'import package_manager'")
+    system Formula["[email protected]"].opt_bin/"python3", "setup.py", "build_ext", "--inplace"
+    assert_match phrase, shell_output("#{Formula["[email protected]"].opt_bin}/python3 -c 'import package_manager'")
   end
 end