Add :fortran requirement

3 files changed, 28 insertions, 2 deletions

diff --git a/Library/Homebrew/dependency_collector.rb b/Library/Homebrew/dependency_collector.rb
index 50dffaab6..7eb05172a 100644
--- a/Library/Homebrew/dependency_collector.rb
+++ b/Library/Homebrew/dependency_collector.rb
@@ -93,6 +93,7 @@ class DependencyCollector
     when :macos      then MinimumMacOSRequirement.new(tags)
     when :mysql      then MysqlDependency.new(tags)
     when :postgresql then PostgresqlDependency.new(tags)
+    when :fortran    then FortranRequired.new(tags)
     when :tex        then TeXDependency.new(tags)
     when :clt        then CLTDependency.new(tags)
     when :arch       then ArchRequirement.new(tags)
diff --git a/Library/Homebrew/requirements.rb b/Library/Homebrew/requirements.rb
index 627fb1f9e..355fad26d 100644
--- a/Library/Homebrew/requirements.rb
+++ b/Library/Homebrew/requirements.rb
@@ -1,9 +1,10 @@
 require 'requirement'
+require 'requirements/fortran_dependency'
 require 'requirements/language_module_dependency'
-require 'requirements/x11_dependency'
+require 'requirements/macos_requirement'
 require 'requirements/mpi_dependency'
 require 'requirements/python_dependency'
-require 'requirements/macos_requirement'
+require 'requirements/x11_dependency'
 
 class XcodeDependency < Requirement
   fatal true
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