diff --git a/pkgs/tools/security/hologram/default.nix b/pkgs/tools/security/hologram/default.nix
index c4e90bd94bb2..ebb884378267 100644
--- a/pkgs/tools/security/hologram/default.nix
+++ b/pkgs/tools/security/hologram/default.nix
@@ -2,13 +2,12 @@
 
 buildGoPackage rec {
   pname = "hologram";
-  version = "2018-03-19";
-  rev = "a7bab58642b530edb75b9cf6c1d834c85822ceac";
+  version = "unstable-2018-03-19";
 
   src = fetchFromGitHub {
     owner = "AdRoll";
     repo = "hologram";
-    inherit rev;
+    rev = "a7bab58642b530edb75b9cf6c1d834c85822ceac";
     sha256 = "00scryz8js6gbw8lp2y23qikbazz2dd992r97rqh0l1q4baa0ckn";
   };
 
diff --git a/pkgs/tools/security/mbox/default.nix b/pkgs/tools/security/mbox/default.nix
index d7a303a3672f..a39d226aac57 100644
--- a/pkgs/tools/security/mbox/default.nix
+++ b/pkgs/tools/security/mbox/default.nix
@@ -2,7 +2,7 @@
 
 stdenv.mkDerivation {
   pname = "mbox";
-  version = "20140526";
+  version = "unstable-2014-05-26";
 
   src = fetchFromGitHub {
     owner = "tsgates";
@@ -28,13 +28,12 @@ stdenv.mkDerivation {
     ./testall.sh
   '';
 
-  meta = with lib;
-    { description = "Lightweight sandboxing mechanism that any user can use without special privileges";
-      homepage = "http://pdos.csail.mit.edu/mbox/";
-      maintainers = with maintainers; [ ehmry ];
-      license = licenses.bsd3;
-      platforms = [ "x86_64-linux" ];
-      broken = true;
-    };
-
+  meta = with lib;    {
+    description = "Lightweight sandboxing mechanism that any user can use without special privileges";
+    homepage = "http://pdos.csail.mit.edu/mbox/";
+    maintainers = with maintainers; [ ehmry ];
+    license = licenses.bsd3;
+    platforms = [ "x86_64-linux" ];
+    broken = true;
+  };
 }
diff --git a/pkgs/tools/security/meo/default.nix b/pkgs/tools/security/meo/default.nix
index 4b96f2b42c23..491bef3e0543 100644
--- a/pkgs/tools/security/meo/default.nix
+++ b/pkgs/tools/security/meo/default.nix
@@ -2,7 +2,7 @@
 
 stdenv.mkDerivation {
   pname = "meo";
-  version = "20121113";
+  version = "unstable-2012-11-13";
 
   src = fetchhg {
     url = "http://oss.stamfest.net/hg/meo";
@@ -25,12 +25,12 @@ stdenv.mkDerivation {
     cp meo-gui/meo-gui $out/bin
   '';
 
-  meta = {
+  meta = with lib; {
     homepage = "http://oss.stamfest.net/wordpress/meo-multiple-eyepairs-only";
     description = "Tools to use cryptography for things like four-eyes principles";
-    license = lib.licenses.agpl3Plus;
-    maintainers = with lib.maintainers; [viric];
-    platforms = with lib.platforms; linux;
+    license = licenses.agpl3Plus;
+    maintainers = with maintainers; [ viric ];
+    platforms = platforms.linux;
     broken = true;
   };
 }
diff --git a/pkgs/tools/security/pwgen/default.nix b/pkgs/tools/security/pwgen/default.nix
index fc410f19843b..6da6c1e1741b 100644
--- a/pkgs/tools/security/pwgen/default.nix
+++ b/pkgs/tools/security/pwgen/default.nix
@@ -1,17 +1,22 @@
-{lib, stdenv, fetchurl, autoreconfHook}:
+{ lib, stdenv, fetchFromGitHub, autoreconfHook }:
+
 stdenv.mkDerivation rec {
   pname = "pwgen";
   version = "2.08";
 
-  src = fetchurl {
-    url = "https://github.com/tytso/pwgen/archive/v${version}.tar.gz";
-    sha256 = "8d6e94f28655e61d6126290e3eafad4d17d7fba0d0d354239522a740a270bb2f";
+  src = fetchFromGitHub {
+    owner = "tytso";
+    repo = "pwgen";
+    rev = "v${version}";
+    sha256 = "8d6e94f58655e61d6126290e3eafad4d17d7fba0d0d354239522a740a270bb2f";
   };
 
   nativeBuildInputs = [ autoreconfHook ];
 
-  meta = {
+  meta = with lib; {
     description = "Password generator which creates passwords which can be easily memorized by a human";
-    platforms = lib.platforms.all;
+    maintainers = with maintainers; [ ];
+    license = with licenses; [ gpl2Only ];
+    platforms = platforms.all;
   };
 }
diff --git a/pkgs/tools/system/ipmitool/default.nix b/pkgs/tools/system/ipmitool/default.nix
index 416fab94ddc9..2ad0d11f95f0 100644
--- a/pkgs/tools/system/ipmitool/default.nix
+++ b/pkgs/tools/system/ipmitool/default.nix
@@ -1,11 +1,8 @@
 { stdenv, lib, fetchurl, openssl, fetchpatch, static ? stdenv.hostPlatform.isStatic }:
 
-let
+stdenv.mkDerivation rec {
   pname = "ipmitool";
   version = "1.8.18";
-in
-stdenv.mkDerivation {
-  inherit pname version;
 
   src = fetchurl {
     url = "mirror://sourceforge/${pname}/${pname}-${version}.tar.gz";
diff --git a/pkgs/tools/system/loadwatch/default.nix b/pkgs/tools/system/loadwatch/default.nix
index 722e5a9afde1..27e33a22d4b9 100644
--- a/pkgs/tools/system/loadwatch/default.nix
+++ b/pkgs/tools/system/loadwatch/default.nix
@@ -1,17 +1,20 @@
-{ lib, stdenv, fetchgit, ... }:
+{ lib, stdenv, fetchgit }:
 
 stdenv.mkDerivation {
   pname = "loadwatch";
   version = "1.1-1-g6d2544c";
+
   src = fetchgit {
     url = "git://woffs.de/git/fd/loadwatch.git";
     sha256 = "1bhw5ywvhyb6snidsnllfpdi1migy73wg2gchhsfbcpm8aaz9c9b";
     rev = "6d2544c0caaa8a64bbafc3f851e06b8056c30e6e";
   };
+
   installPhase = ''
     mkdir -p $out/bin
     install loadwatch lw-ctl $out/bin
   '';
+
   meta = with lib; {
     description = "Run a program using only idle cycles";
     license = licenses.gpl2;
diff --git a/pkgs/tools/system/localtime/default.nix b/pkgs/tools/system/localtime/default.nix
index 4c12c9eb27da..0ad17c6c6595 100644
--- a/pkgs/tools/system/localtime/default.nix
+++ b/pkgs/tools/system/localtime/default.nix
@@ -2,7 +2,7 @@
 
 buildGoPackage rec {
   pname = "localtime";
-  version = "2017-11-07";
+  version = "unstable-2017-11-07";
 
   src = fetchFromGitHub {
     owner = "Stebalien";
@@ -32,6 +32,7 @@ buildGoPackage rec {
   meta = with lib; {
     description = "A daemon for keeping the system timezone up-to-date based on the current location";
     homepage = "https://github.com/Stebalien/localtime";
+    maintainers = with maintainers; [ ];
     platforms = platforms.linux;
     license = licenses.gpl3;
   };
diff --git a/pkgs/tools/system/opencl-info/default.nix b/pkgs/tools/system/opencl-info/default.nix
index 173de5f607fe..124b53512d72 100644
--- a/pkgs/tools/system/opencl-info/default.nix
+++ b/pkgs/tools/system/opencl-info/default.nix
@@ -2,7 +2,7 @@
 
 stdenv.mkDerivation {
   pname = "opencl-info";
-  version = "2014-02-21";
+  version = "unstable-2014-02-21";
 
   src = fetchFromGitHub {
     owner = "marchv";
diff --git a/pkgs/tools/system/rowhammer-test/default.nix b/pkgs/tools/system/rowhammer-test/default.nix
index 685697f861ff..993bfdaf834a 100644
--- a/pkgs/tools/system/rowhammer-test/default.nix
+++ b/pkgs/tools/system/rowhammer-test/default.nix
@@ -2,12 +2,12 @@
 
 stdenv.mkDerivation {
   pname = "rowhammer-test";
-  version = "20150811";
+  version = "unstable-2015-08-11";
 
   src = fetchFromGitHub {
     owner = "google";
     repo = "rowhammer-test";
-    rev = "c1d2bd9f629281402c10bb10e52bc1f1faf59cc4"; # 2015-08-11
+    rev = "c1d2bd9f629281402c10bb10e52bc1f1faf59cc4";
     sha256 = "1fbfcnm5gjish47wdvikcsgzlb5vnlfqlzzm6mwiw2j5qkq0914i";
   };