ffmpeg: fix version stamp for HEAD builds

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/Library/Formula/ffmpeg.rb b/Library/Formula/ffmpeg.rb
index c06f3a1b7..7ed359eb8 100644
--- a/Library/Formula/ffmpeg.rb
+++ b/Library/Formula/ffmpeg.rb
@@ -53,6 +53,29 @@ class Ffmpeg < Formula
       end
     end
 
+    write_version_file if ARGV.build_head?
+
     system "make install"
   end
+
+  # Makefile expects to run in git repo and generate a version number
+  # with 'git describe --always' (see version.sh) but Homebrew build
+  # runs in temp copy created via git checkout-index, so 'git describe'
+  # does not work. Work around by writing VERSION file in build directory
+  # to be picked up by version.sh.  Note that VERSION file will already
+  # exist in release versions, so this only applies to git HEAD builds.
+  def write_version_file
+    return if File.exists?("VERSION")
+    git_tag = "UNKNOWN"
+    Dir.chdir(cached_download) do
+      ret = `git describe --always`
+      if not $?.success?
+        opoo "Could not determine build version from git repository - set to #{git_tag}"
+      else
+        git_tag = ret
+      end
+    end
+    File.open("VERSION","w") {|f| f.puts "git-#{git_tag}"}
+  end
+
 end