[Homebrew](http://brew.sh) formula for datetime-fortran.

datetime-fortran.rb

class DatetimeFortran < Formula
  desc "Fortran time and date manipulation library"
  homepage "https://github.com/milancurcic/datetime-fortran"
  url "https://github.com/milancurcic/datetime-fortran/archive/v1.4.2.tar.gz"
  sha256 "b500da7e28241ffecb3d06d93fc4d25df71509cb949e472e92a96df843a9f4c9"

  head do
    url "https://github.com/milancurcic/datetime-fortran.git"

    depends_on "autoconf"   => :build
    depends_on "automake"   => :build
    depends_on "pkg-config" => :build
  end

  option "without-test", "Run build time tests"
  depends_on :fortran

  def install
    system "autoreconf", "-fvi" if build.head?
    system "./configure", "--prefix=#{prefix}",
                          "--disable-silent-rules"
    system "make", "check" if build.with? "test"
    system "make", "install"
    (pkgshare/"test").install "src/tests/datetime_tests.f90"
  end

  test do
    ENV.fortran
    system ENV.fc, "-odatetime_test", "-ldatetime", "-I#{HOMEBREW_PREFIX}/include", pkgshare/"test/datetime_tests.f90"
    system testpath/"datetime_test"
  end
end

utetime-fortran.rb

class DatetimeFortran < Formula
  desc "Fortran time and date manipulation library"
  homepage "https://github.com/milancurcic/datetime-fortran"
  url "https://github.com/milancurcic/datetime-fortran/archive/v1.4.2.tar.gz"
  sha256 "a164d377884828b43c01a46ebbc0e95f7549dd8ea198ee9868f3b9eddf3addf3"

  head do
    url "https://github.com/milancurcic/datetime-fortran.git"

    depends_on "autoconf"   => :build
    depends_on "automake"   => :build
    depends_on "pkg-config" => :build
  end

  option "without-test", "Run build time tests"
  depends_on :fortran

  def install
    system "autoreconf", "-fvi" if build.head?
    system "./configure", "--prefix=#{prefix}",
                          "--disable-silent-rules"
    system "make", "check" if build.with? "test"
    system "make", "install"
    (pkgshare/"test").install "src/tests/datetime_tests.f90"
  end

  test do
    ENV.fortran
    system ENV.fc, "-odatetime_test", "-ldatetime", "-I#{HOMEBREW_PREFIX}/include", pkgshare/"test/datetime_tests.f90"
    system testpath/"datetime_test"
  end
end

Very neat-looking.

I would love to parse the output of system testpath/"datetime_test" for /FAIL/ but my ruby is sadly too limited to figure out how to do this...

!assert_match /FAIL.*/, `#{testpath}/datetime_test`

from Homebrew/legacy-homebrew#48660