uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/development/interpreters/ruby/rubygems/0001-add-post-extract-hook.patch

@@ -0,0 +1,34 @@
+From a6485cfcdf51ff8be452980f93cebfea97f34dec Mon Sep 17 00:00:00 2001
+From: zimbatm <zimbatm@zimbatm.com>
+Date: Wed, 21 Sep 2016 09:32:34 +0100
+Subject: [PATCH 1/3] add post-extract hook
+
+Allows nix to execute scripts just after the gem extraction
+---
+ lib/rubygems/installer.rb | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/lib/rubygems/installer.rb b/lib/rubygems/installer.rb
+index d26b1e88..bf18fb7f 100644
+--- a/lib/rubygems/installer.rb
++++ b/lib/rubygems/installer.rb
+@@ -848,7 +848,15 @@ TEXT
+   # Ensures that files can't be installed outside the gem directory.
+ 
+   def extract_files
+-    @package.extract_files gem_dir
++    ret = @package.extract_files gem_dir
++    if ENV['NIX_POST_EXTRACT_FILES_HOOK']
++      puts
++      puts "running NIX_POST_EXTRACT_FILES_HOOK #{ENV['NIX_POST_EXTRACT_FILES_HOOK']} #{gem_dir}"
++      system(ENV['NIX_POST_EXTRACT_FILES_HOOK'], gem_dir.to_s)
++      puts "running NIX_POST_EXTRACT_FILES_HOOK done"
++      puts
++    end
++    ret
+   end
+ 
+   ##
+-- 
+2.21.0
+

pkgs/development/interpreters/ruby/rubygems/0002-binaries-with-env-shebang.patch

@@ -0,0 +1,28 @@
+From 2e1328bcdddd35e557eabdff83ac07f3591dc693 Mon Sep 17 00:00:00 2001
+From: zimbatm <zimbatm@zimbatm.com>
+Date: Wed, 21 Sep 2016 19:37:05 +0100
+Subject: [PATCH 2/3] binaries with env shebang
+
+By default, don't point to the absolute ruby derivation path. As a user
+installing a gem in the home, it would freeze the selected ruby version
+to the currently-installed ruby derivation.
+---
+ lib/rubygems/dependency_installer.rb | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/rubygems/dependency_installer.rb b/lib/rubygems/dependency_installer.rb
+index 34620860..00ab31d9 100644
+--- a/lib/rubygems/dependency_installer.rb
++++ b/lib/rubygems/dependency_installer.rb
+@@ -18,7 +18,7 @@ class Gem::DependencyInstaller
+   extend Gem::Deprecate
+ 
+   DEFAULT_OPTIONS = { # :nodoc:
+-    :env_shebang         => false,
++    :env_shebang         => true,
+     :document            => %w[ri],
+     :domain              => :both, # HACK dup
+     :force               => false,
+-- 
+2.21.0
+

pkgs/development/interpreters/ruby/rubygems/0003-gem-install-default-to-user.patch

@@ -0,0 +1,26 @@
+From d69249d0ff210316121b44d971ddd2439b1bc393 Mon Sep 17 00:00:00 2001
+From: zimbatm <zimbatm@zimbatm.com>
+Date: Wed, 21 Sep 2016 09:40:39 +0100
+Subject: [PATCH 3/3] gem install default to user
+
+Default to not installing gems to the read-only system derivation.
+---
+ lib/rubygems/path_support.rb | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/lib/rubygems/path_support.rb b/lib/rubygems/path_support.rb
+index ed680d65..749b9ea6 100644
+--- a/lib/rubygems/path_support.rb
++++ b/lib/rubygems/path_support.rb
+@@ -23,7 +23,7 @@ class Gem::PathSupport
+   # hashtable, or defaults to ENV, the system environment.
+   #
+   def initialize(env)
+-    @home = env["GEM_HOME"] || Gem.default_dir
++    @home = env["GEM_HOME"] || Gem.user_dir
+ 
+     if File::ALT_SEPARATOR
+       @home = @home.gsub(File::ALT_SEPARATOR, File::SEPARATOR)
+-- 
+2.21.0
+

pkgs/development/interpreters/ruby/rubygems/default.nix

@@ -0,0 +1,30 @@
+{ stdenv, lib, fetchurl }:
+
+stdenv.mkDerivation rec {
+  pname = "rubygems";
+  version = "3.2.26";
+
+  src = fetchurl {
+    url = "https://rubygems.org/rubygems/rubygems-${version}.tgz";
+    sha256 = "sha256-9wa6lOWnua8zBblQKRgjjiTVPYp2TW0n7XOvgW7u1e8=";
+  };
+
+  patches = [
+    ./0001-add-post-extract-hook.patch
+    ./0002-binaries-with-env-shebang.patch
+    ./0003-gem-install-default-to-user.patch
+  ];
+
+  installPhase = ''
+    runHook preInstall
+    cp -r . $out
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "Package management framework for Ruby";
+    homepage = "https://rubygems.org/";
+    license = with licenses; [ mit /* or */ ruby ];
+    maintainers = with maintainers; [ zimbatm ];
+  };
+}