notary: fix build

The package is broken on master for some time now:
https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.notary.x86_64-linux/all

The main reason for the breackage is that the `Makefile` script attempts
to retrieve the latest git commit by using `git rev-parse` which breaks
as `git` is not in the build environment. This could be fixed by using
`?=` rather than `:=` for the `GITCOMMIT` variable in the `make` script
to easily override `GITCOMMIT` in the `buildPhase`.

See the Hydra logs for reference:
https://nix-cache.s3.amazonaws.com/log/ib4qp8h4r8d830ra4fah38l7ybb82gp7-notary-0.6.0.drv

Furthermore some refactoring was applied:

* Activated the test suite for `cmd/notary` to confirm the basic
  functionality when building for NixOS.

* Added {pre,post} hooks for `{build,install}Phase`

* Added myself as maintainer to have more people available in case of
  further breakage.

pkgs/tools/security/notary/default.nix

@@ -1,32 +1,42 @@
-{ stdenv, fetchFromGitHub, buildGoPackage, git, libtool }:
+{ stdenv, fetchFromGitHub, buildGoPackage, libtool }:
 
 buildGoPackage rec {
   name = "notary-${version}";
-  version = "0.6.0";
-  gitcommit = "34f53ad";
+  version = "0.6.1";
+  gitcommit = "d6e1431f";
 
   src = fetchFromGitHub {
     owner = "theupdateframework";
     repo = "notary";
     rev = "v${version}";
-    sha256 = "0lg7ab2agkk3rnladcvpdzk8cnf3m49qfm4sanh7yjvlvlv1wm4a";
+    sha256 = "1ak9dk6vjny5069hp3w36dbjawcnaq82l3i2qvf7mn7zfglbsnf9";
   };
 
+  patches = [ ./no-git-usage.patch ];
+
   buildInputs = [ libtool ];
+  buildPhase = ''
+    runHook preBuild
+    cd go/src/github.com/theupdateframework/notary
+    make client GITCOMMIT=${gitcommit}
+    runHook postBuild
+  '';
 
   goPackagePath = "github.com/theupdateframework/notary";
 
-  buildPhase = ''
-    cd go/src/github.com/theupdateframework/notary
-    make GITCOMMIT=${gitcommit} GITUNTRACKEDCHANGES= client
+  installPhase = ''
+    runHook preInstall
+    install -D bin/notary $bin/bin/notary
+    runHook postInstall
   '';
 
-  installPhase = ''
-    install -D bin/notary $bin/bin/notary
+  doCheck = true;
+  checkPhase = ''
+    make test PKGS=github.com/theupdateframework/notary/cmd/notary
   '';
 
   meta = with stdenv.lib; {
-    description = " Notary is a project that allows anyone to have trust over arbitrary collections of data";
+    description = "Notary is a project that allows anyone to have trust over arbitrary collections of data";
     longDescription = ''
       The Notary project comprises a server and a client for running and
       interacting with trusted collections. See the service architecture
@@ -49,7 +59,7 @@ buildGoPackage rec {
     '';
     license = licenses.asl20;
     homepage = https://github.com/theupdateframework/notary;
-    maintainers = with maintainers; [ vdemeester ];
-    platforms = with platforms; unix;
+    maintainers = with maintainers; [ vdemeester ma27 ];
+    platforms = platforms.unix;
   };
 }

pkgs/tools/security/notary/no-git-usage.patch

@@ -0,0 +1,15 @@
+diff --git a/Makefile b/Makefile
+index ab794165..0cbd047f 100644
+--- a/Makefile
++++ b/Makefile
+@@ -5,8 +5,8 @@ PREFIX?=$(shell pwd)
+ # Add to compile time flags
+ NOTARY_PKG := github.com/theupdateframework/notary
+ NOTARY_VERSION := $(shell cat NOTARY_VERSION)
+-GITCOMMIT := $(shell git rev-parse --short HEAD)
+-GITUNTRACKEDCHANGES := $(shell git status --porcelain --untracked-files=no)
++GITCOMMIT ?= $(shell git rev-parse --short HEAD)
++GITUNTRACKEDCHANGES :=
+ ifneq ($(GITUNTRACKEDCHANGES),)
+ GITCOMMIT := $(GITCOMMIT)-dirty
+ endif