nushell 0.2.0 (new formula)

Closes #43440.

Signed-off-by: Misty De Meo <mistydemeo@github.com>

Formula/nushell.rb

@@ -0,0 +1,28 @@
+class Nushell < Formula
+  desc "Modern shell for the GitHub era"
+  homepage "https://www.nushell.sh"
+  url "https://github.com/nushell/nushell/archive/0.2.0.tar.gz"
+  sha256 "5bce8cdb33a6580ff15214322bc66945c0b4d93375056865ad30e0415fece3de"
+  head "https://github.com/nushell/nushell.git"
+
+  depends_on "openssl"
+
+  # Nu requires features from Rust 1.39 to build, so we can't use Homebrew's
+  # Rust; picking a known-good Rust nightly release to use instead.
+  resource "rust-nightly" do
+    url "https://static.rust-lang.org/dist/2019-08-24/rust-nightly-x86_64-apple-darwin.tar.xz"
+    sha256 "104ddea51b758f4962960097e9e0f3cabf2c671ec3148bc745344431bb93605d"
+  end
+
+  def install
+    resource("rust-nightly").stage do
+      system "./install.sh", "--prefix=#{buildpath}/rust-nightly"
+      ENV.prepend_path "PATH", "#{buildpath}/rust-nightly/bin"
+    end
+    system "cargo", "install", "--root", prefix, "--path", "."
+  end
+
+  test do
+    assert_equal "#{Dir.pwd}> 2\n#{Dir.pwd}> CTRL-D\n", pipe_output("#{bin}/nu", 'echo \'{"foo":1, "bar":2}\' | from-json | get bar | echo $it')
+  end
+end