Add :fortran requirement

1 files changed, 24 insertions, 0 deletions

diff --git a/Library/Homebrew/requirements/fortran_dependency.rb b/Library/Homebrew/requirements/fortran_dependency.rb
new file mode 100644
index 000000000..0de239e4e
--- /dev/null
+++ b/Library/Homebrew/requirements/fortran_dependency.rb
@@ -0,0 +1,24 @@
+require 'requirement'
+
+class FortranRequired < Requirement
+  fatal true
+
+  default_formula 'gfortran'
+
+  env { ENV.fortran }
+
+  satisfy :build_env => false do
+    (ENV['FC'] || which('gfortran')) ? true : false
+  end
+
+  def message; <<-EOS.undent
+    Fortran is required to install.
+
+    You can install this with Homebrew using:
+      brew install gfortran
+
+    Or you can use an external compiler by setting:
+      FC=<path-to-fortran-compiler>
+    EOS
+  end
+end