Python 2.x and 3.x support

New `depends_on :python` Dependency.
New `depends_on :python3` Dependency.

To avoid having multiple formulae with endings -py2 and -py3,
we will handle support for different pythons (2.x vs. 3.x)
in the same formula.
Further brewed vs. external python will be transparently supported.

The formula also gets a new object `python`, which is false if
no Python is available or the user has disabled it. Otherwise
it is defined and provides several support methods:

python.site_packages # the site-packages in the formula's Cellar
python.global_site_packages
python.binary # the full path to the python binary
python.prefix
python.version
python.version.major
python.version.minor
python.xy # => e.g. "python2.7"
python.incdir # includes of python
python.libdir # the python dylib library
python.pkg_config_path # used internally by brew
python.from_osx?
python.framework?
python.universal?
python.pypy?
python.standard_caveats # Text to set PYTHONPATH for python.from_osx?
python.if3then3 # => "" for 2.x and to "3" for 3.x.

Further, to avoid code duplication, `python` takes an optional
block that is run twice if the formula defines depends_on
:python AND :python3.

python do
  system python, 'setup.py', "--prefix=#{prefix}"
end

Read more in the Homebrew wiki.

1 files changed, 16 insertions, 3 deletions

diff --git a/Library/Formula/beecrypt.rb b/Library/Formula/beecrypt.rb
index 59e6c6e7f..a976f8b71 100644
--- a/Library/Formula/beecrypt.rb
+++ b/Library/Formula/beecrypt.rb
@@ -6,6 +6,7 @@ class Beecrypt < Formula
   sha256 '286f1f56080d1a6b1d024003a5fa2158f4ff82cae0c6829d3c476a4b5898c55d'
 
   depends_on "icu4c"
+  depends_on :python => :optional
 
   def patches
     # fix build with newer clang, gcc 4.7 (https://bugs.gentoo.org/show_bug.cgi?id=413951)
@@ -19,15 +20,27 @@ class Beecrypt < Formula
   end
 
   def install
-    ENV.remove_from_cflags /-march=\S*/
-    args = ["--prefix=#{prefix}", "--disable-openmp", "--without-java", "--without-python"]
+    ENV.remove_from_cflags(/-march=\S*/)
+    args = ["--prefix=#{prefix}", "--disable-openmp", "--without-java"]
     if MacOS.prefer_64_bit?
       args << "--build=x86_64-apple-darwin#{darwin_major_version}"
     end
+
+    args << "--without-python" if build.without? 'python'
+
+    if python
+      # We don't want beecrypt to use get_python_lib() to install into
+      # the global site-packages. There is no option to set it.
+      # Fixing this in configure make the configure output printout correct.
+      inreplace "configure", "ac_cv_python_libdir=`$PYTHON -c 'import distutils.sysconfig; print distutils.sysconfig.get_python_lib()'`",
+                             "ac_cv_python_libdir='#{python.site_packages}'"
+    end
     system "./configure", *args
     system "make"
-    system "make check"
     system "make install"
+    # We have to move the check after install (which is stupid, I know) but
+    # otherwise they fail because python bindings don't yet find the libbeecrypt
+    system "make check"
   end
 end