Improve python tests for brew bots

Allow `build.with?` and similar methods to be used during the test
phase. The BuildOptions (`build`) are initialized with the
`Tab.used_options` unless explicitly overwritten on the command line.

So basically `build.with?` works in `def install` and in `test do` as
one would naively expect. (For the test, gramatically it should be
`built.with?` but who cares)

If a formula was installed `--with-python`, now the tests are also
run `--with-python`. This enables us to use the `python do ... end` in
a meaningful manner.

Using `python do ... end` blocks for the tests, because the bot.brew.sh has
system python per default and we need to set the PYTHONPATH for the test.
Potentially to different values for Python 2.x and 3.x.

1 files changed, 4 insertions, 6 deletions

diff --git a/Library/Formula/libvirt.rb b/Library/Formula/libvirt.rb
index 6b88d28a2..f47bb0b7e 100644
--- a/Library/Formula/libvirt.rb
+++ b/Library/Formula/libvirt.rb
@@ -63,12 +63,10 @@ class Libvirt < Formula
   end
 
   test do
-    if build.with? 'python'
-      python do
-        # Testing to import the mod because that is a .so file where linking
-        # can break.
-        system python, '-c', "import libvirtmod"
-      end
+    python do
+      # Testing to import the mod because that is a .so file where linking
+      # can break.
+      system python, '-c', "import libvirtmod"
     end
   end
 end