diff --git a/pkgs/development/interpreters/clojure/clooj.nix b/pkgs/development/interpreters/clojure/clooj.nix
index 810d783d4fb5..42d6d67ee15b 100644
--- a/pkgs/development/interpreters/clojure/clooj.nix
+++ b/pkgs/development/interpreters/clojure/clooj.nix
@@ -1,14 +1,12 @@
 { lib, stdenv, fetchurl, jre, makeWrapper }:
 
-let version = "0.4.4"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "clooj";
-  inherit version;
+  version = "0.4.4";
 
   jar = fetchurl {
     # mirrored as original mediafire.com source does not work without user interaction
-    url = "https://archive.org/download/clooj-0.4.4-standalone/clooj-0.4.4-standalone.jar";
+    url = "https://archive.org/download/clooj-${version}-standalone/clooj-${version}-standalone.jar";
     sha256 = "0hbc29bg2a86rm3sx9kvj7h7db9j0kbnrb706wsfiyk3zi3bavnd";
   };
 
diff --git a/pkgs/development/interpreters/eff/default.nix b/pkgs/development/interpreters/eff/default.nix
index 8dba500c15bd..cddb773ec168 100644
--- a/pkgs/development/interpreters/eff/default.nix
+++ b/pkgs/development/interpreters/eff/default.nix
@@ -1,11 +1,8 @@
 { lib, stdenv, fetchFromGitHub, which, ocamlPackages }:
 
-let version = "5.0"; in
-
-stdenv.mkDerivation {
-
+stdenv.mkDerivation rec {
   pname = "eff";
-  inherit version;
+  version = "5.0";
 
   src = fetchFromGitHub {
     owner = "matijapretnar";
diff --git a/pkgs/development/interpreters/gnu-apl/default.nix b/pkgs/development/interpreters/gnu-apl/default.nix
index 108da08b80d7..0f666dd9af5d 100644
--- a/pkgs/development/interpreters/gnu-apl/default.nix
+++ b/pkgs/development/interpreters/gnu-apl/default.nix
@@ -36,7 +36,6 @@ stdenv.mkDerivation rec {
     license     = licenses.gpl3Plus;
     maintainers = [ maintainers.kovirobi ];
     platforms   = with platforms; linux ++ darwin;
-    inherit version;
     mainProgram = "apl";
 
     longDescription = ''
diff --git a/pkgs/development/interpreters/pyrex/0.9.5.nix b/pkgs/development/interpreters/pyrex/0.9.5.nix
index a9c71c6fcf70..3fb909b0bb0d 100644
--- a/pkgs/development/interpreters/pyrex/0.9.5.nix
+++ b/pkgs/development/interpreters/pyrex/0.9.5.nix
@@ -1,10 +1,8 @@
 { lib, fetchurl, python2Packages }:
 
-let version = "0.9.5.1.1"; in
-
-python2Packages.buildPythonPackage {
+python2Packages.buildPythonPackage rec {
   pname = "pyrex";
-  inherit version;
+  version = "0.9.5.1.1";
 
   src = fetchurl {
     url = "https://www.cosc.canterbury.ac.nz/greg.ewing/python/Pyrex/oldtar/Pyrex-${version}.tar.gz";
diff --git a/pkgs/development/interpreters/pyrex/0.9.6.nix b/pkgs/development/interpreters/pyrex/0.9.6.nix
index 12429c05fe63..e9d8d3097093 100644
--- a/pkgs/development/interpreters/pyrex/0.9.6.nix
+++ b/pkgs/development/interpreters/pyrex/0.9.6.nix
@@ -1,10 +1,8 @@
 { lib, fetchurl, python2Packages }:
 
-let version = "0.9.6.4"; in
-
-python2Packages.buildPythonPackage {
+python2Packages.buildPythonPackage rec {
   pname = "pyrex";
-  inherit version;
+  version = "0.9.6.4";
 
   src = fetchurl {
     url = "https://www.cosc.canterbury.ac.nz/greg.ewing/python/Pyrex/oldtar/Pyrex-${version}.tar.gz";
diff --git a/pkgs/development/libraries/afflib/default.nix b/pkgs/development/libraries/afflib/default.nix
index 94970c5a308a..cb0c8025ddfa 100644
--- a/pkgs/development/libraries/afflib/default.nix
+++ b/pkgs/development/libraries/afflib/default.nix
@@ -24,7 +24,6 @@ stdenv.mkDerivation rec {
     platforms = lib.platforms.unix;
     license = lib.licenses.bsdOriginal;
     maintainers = [ lib.maintainers.raskin ];
-    inherit version;
     downloadPage = "https://github.com/sshock/AFFLIBv3/tags";
   };
 }
diff --git a/pkgs/development/libraries/bctoolbox/default.nix b/pkgs/development/libraries/bctoolbox/default.nix
index 9cdede785283..1a42211b9393 100644
--- a/pkgs/development/libraries/bctoolbox/default.nix
+++ b/pkgs/development/libraries/bctoolbox/default.nix
@@ -27,7 +27,6 @@ stdenv.mkDerivation rec {
   NIX_CFLAGS_COMPILE = [ "-Wno-error=stringop-truncation" ];
 
   meta = with lib; {
-    inherit version;
     description = "Utilities library for Linphone";
     homepage = "https://gitlab.linphone.org/BC/public/bctoolbox";
     license = licenses.gpl3Plus;
diff --git a/pkgs/development/libraries/botan/generic.nix b/pkgs/development/libraries/botan/generic.nix
index 2fc5abc2928a..3313b8c4fcd1 100644
--- a/pkgs/development/libraries/botan/generic.nix
+++ b/pkgs/development/libraries/botan/generic.nix
@@ -45,7 +45,6 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with lib; {
-    inherit version;
     description = "Cryptographic algorithms library";
     maintainers = with maintainers; [ raskin ];
     platforms = platforms.unix;
diff --git a/pkgs/development/libraries/csfml/default.nix b/pkgs/development/libraries/csfml/default.nix
index 78d8bce40a36..cfc41b9271be 100644
--- a/pkgs/development/libraries/csfml/default.nix
+++ b/pkgs/development/libraries/csfml/default.nix
@@ -1,12 +1,8 @@
 { lib, stdenv, fetchFromGitHub, cmake, sfml }:
 
-let
-  version = "2.5";
-in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "csfml";
-  inherit version;
+  version = "2.5";
   src = fetchFromGitHub {
     owner = "SFML";
     repo  = "CSFML";
diff --git a/pkgs/development/libraries/flint/default.nix b/pkgs/development/libraries/flint/default.nix
index 475428167060..7f814461f282 100644
--- a/pkgs/development/libraries/flint/default.nix
+++ b/pkgs/development/libraries/flint/default.nix
@@ -41,7 +41,6 @@ stdenv.mkDerivation rec {
 
   doCheck = true;
   meta = {
-    inherit version;
     description = "Fast Library for Number Theory";
     license = lib.licenses.gpl2Plus;
     maintainers = lib.teams.sage.members;
diff --git a/pkgs/development/libraries/fplll/20160331.nix b/pkgs/development/libraries/fplll/20160331.nix
index 374aec5904d6..6bb9570d998a 100644
--- a/pkgs/development/libraries/fplll/20160331.nix
+++ b/pkgs/development/libraries/fplll/20160331.nix
@@ -13,7 +13,6 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [autoconf automake libtool gettext autoreconfHook];
   buildInputs = [gmp mpfr];
   meta = {
-    inherit version;
     description = "Lattice algorithms using floating-point arithmetic";
     license = lib.licenses.lgpl21Plus;
     maintainers = [lib.maintainers.raskin];
diff --git a/pkgs/development/libraries/freeglut/default.nix b/pkgs/development/libraries/freeglut/default.nix
index 83e3eebdcc32..ecdc1c19ff14 100644
--- a/pkgs/development/libraries/freeglut/default.nix
+++ b/pkgs/development/libraries/freeglut/default.nix
@@ -1,9 +1,8 @@
 { lib, stdenv, fetchurl, libXi, libXrandr, libXxf86vm, libGL, libGLU, xlibsWrapper, cmake }:
 
-let version = "3.2.1";
-in stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "freeglut";
-  inherit version;
+  version = "3.2.1";
 
   src = fetchurl {
     url = "mirror://sourceforge/freeglut/freeglut-${version}.tar.gz";
diff --git a/pkgs/development/libraries/globalarrays/default.nix b/pkgs/development/libraries/globalarrays/default.nix
index 1f70946cbcec..8b01f9f68146 100644
--- a/pkgs/development/libraries/globalarrays/default.nix
+++ b/pkgs/development/libraries/globalarrays/default.nix
@@ -2,12 +2,9 @@
 , blas, gfortran, openssh, mpi
 } :
 
-let
-  version = "5.8";
-
-in stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "globalarrays";
-  inherit version;
+  version = "5.8";
 
   src = fetchFromGitHub {
     owner = "GlobalArrays";
diff --git a/pkgs/development/libraries/gloox/default.nix b/pkgs/development/libraries/gloox/default.nix
index b01d858cfb92..82429add2619 100644
--- a/pkgs/development/libraries/gloox/default.nix
+++ b/pkgs/development/libraries/gloox/default.nix
@@ -10,12 +10,9 @@ assert idnSupport -> libidn != null;
 
 with lib;
 
-let
-  version = "1.0.24";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec{
   pname = "gloox";
-  inherit version;
+  version = "1.0.24";
 
   src = fetchurl {
     url = "https://camaya.net/download/gloox-${version}.tar.bz2";
diff --git a/pkgs/development/libraries/highfive/default.nix b/pkgs/development/libraries/highfive/default.nix
index a9db80468ee6..015147d70bc3 100644
--- a/pkgs/development/libraries/highfive/default.nix
+++ b/pkgs/development/libraries/highfive/default.nix
@@ -39,7 +39,6 @@ stdenv.mkDerivation rec {
   ++ (lib.optionals mpiSupport [ "-DHIGHFIVE_PARALLEL_HDF5=ON" ]);
 
   meta = with lib; {
-    inherit version;
     description = "Header-only C++ HDF5 interface";
     license = licenses.boost;
     homepage = "https://bluebrain.github.io/HighFive/";
diff --git a/pkgs/development/libraries/kdsoap/default.nix b/pkgs/development/libraries/kdsoap/default.nix
index 93aa169737bb..a4dd9cbaa45d 100644
--- a/pkgs/development/libraries/kdsoap/default.nix
+++ b/pkgs/development/libraries/kdsoap/default.nix
@@ -3,13 +3,9 @@
 , qtbase
 }:
 
-let
-  version = "1.10.0";
-in
-
-mkDerivation {
+mkDerivation rec {
   pname = "kdsoap";
-  inherit version;
+  version = "1.10.0";
   meta = {
     description = "A Qt-based client-side and server-side SOAP component";
     longDescription = ''
diff --git a/pkgs/development/libraries/libbladeRF/default.nix b/pkgs/development/libraries/libbladeRF/default.nix
index f9bac3835d45..e8b550e06c2a 100644
--- a/pkgs/development/libraries/libbladeRF/default.nix
+++ b/pkgs/development/libraries/libbladeRF/default.nix
@@ -1,6 +1,5 @@
 { stdenv, lib, fetchFromGitHub, fetchpatch, pkg-config, cmake, git, doxygen, help2man, ncurses, tecla
 , libusb1, udev }:
-
 let
   # fetch submodule
   noos = fetchFromGitHub {
@@ -9,12 +8,9 @@ let
     rev = "0bba46e6f6f75785a65d425ece37d0a04daf6157";
     sha256 = "0is79dhsyp9xmlnfdr1i5s1c22ipjafk9d35jpn5dynpvj86m99c";
   };
-
-  version = "2.2.1";
-
-in stdenv.mkDerivation {
+in stdenv.mkDerivation rec {
   pname = "libbladeRF";
-  inherit version;
+  version = "2.2.1";
 
   src = fetchFromGitHub {
     owner = "Nuand";
diff --git a/pkgs/development/libraries/libcec/default.nix b/pkgs/development/libraries/libcec/default.nix
index cb494f69fd11..b0de95923477 100644
--- a/pkgs/development/libraries/libcec/default.nix
+++ b/pkgs/development/libraries/libcec/default.nix
@@ -1,10 +1,8 @@
 { lib, stdenv, fetchurl, cmake, pkg-config, udev, libcec_platform, libraspberrypi ? null }:
 
-let version = "6.0.2"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libcec";
-  inherit version;
+  version = "6.0.2";
 
   src = fetchurl {
     url = "https://github.com/Pulse-Eight/libcec/archive/libcec-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libcec/platform.nix b/pkgs/development/libraries/libcec/platform.nix
index 61eccf1f40ea..45c34b53cd77 100644
--- a/pkgs/development/libraries/libcec/platform.nix
+++ b/pkgs/development/libraries/libcec/platform.nix
@@ -1,10 +1,8 @@
 { lib, stdenv, fetchurl, cmake }:
 
-let version = "2.1.0.1"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "p8-platform";
-  inherit version;
+  version = "2.1.0.1";
 
   src = fetchurl {
     url = "https://github.com/Pulse-Eight/platform/archive/p8-platform-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libdynd/default.nix b/pkgs/development/libraries/libdynd/default.nix
index 4f1fd3904d98..b418279e477b 100644
--- a/pkgs/development/libraries/libdynd/default.nix
+++ b/pkgs/development/libraries/libdynd/default.nix
@@ -1,9 +1,8 @@
 { lib, stdenv, fetchFromGitHub, cmake }:
 
-let version = "0.7.2"; in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libdynd";
-  inherit version;
+  version = "0.7.2";
 
   src = fetchFromGitHub {
     owner = "libdynd";
diff --git a/pkgs/development/libraries/libjson/default.nix b/pkgs/development/libraries/libjson/default.nix
index 16a69f6da653..9106c1974716 100644
--- a/pkgs/development/libraries/libjson/default.nix
+++ b/pkgs/development/libraries/libjson/default.nix
@@ -1,9 +1,8 @@
 { lib, stdenv, fetchurl, unzip }:
-let
-  version = "7.6.1";
-in stdenv.mkDerivation {
+
+stdenv.mkDerivation rec {
   pname = "libjson";
-  inherit version;
+  version = "7.6.1";
   src = fetchurl {
     url = "mirror://sourceforge/libjson/libjson_${version}.zip";
     sha256 = "0xkk5qc7kjcdwz9l04kmiz1nhmi7iszl3k165phf53h3a4wpl9h7";
diff --git a/pkgs/development/libraries/libmodplug/default.nix b/pkgs/development/libraries/libmodplug/default.nix
index 790674f1649e..3f4f89c0a25c 100644
--- a/pkgs/development/libraries/libmodplug/default.nix
+++ b/pkgs/development/libraries/libmodplug/default.nix
@@ -1,10 +1,8 @@
 { lib, stdenv, fetchurl, file }:
 
-let
-  version = "0.8.9.0";
-in stdenv.mkDerivation rec {
+stdenv.mkDerivation rec {
   pname = "libmodplug";
-  inherit version;
+  version = "0.8.9.0";
 
   preConfigure = ''
      substituteInPlace configure \
diff --git a/pkgs/development/libraries/libmpc/default.nix b/pkgs/development/libraries/libmpc/default.nix
index bd28f490ecb7..2dede1f976d2 100644
--- a/pkgs/development/libraries/libmpc/default.nix
+++ b/pkgs/development/libraries/libmpc/default.nix
@@ -7,12 +7,9 @@
 # cgit) that are needed here should be included directly in Nixpkgs as
 # files.
 
-let
-  version = "1.2.1";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libmpc";
-  inherit version; # to avoid clash with the MPD client
+  version = "1.2.1"; # to avoid clash with the MPD client
 
   src = fetchurl {
     url = "mirror://gnu/mpc/mpc-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libopus/default.nix b/pkgs/development/libraries/libopus/default.nix
index 8172bd38e107..6776f5ae3934 100644
--- a/pkgs/development/libraries/libopus/default.nix
+++ b/pkgs/development/libraries/libopus/default.nix
@@ -1,12 +1,9 @@
 { lib, stdenv, fetchurl
 , fixedPoint ? false, withCustomModes ? true }:
 
-let
-  version = "1.3.1";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libopus";
-  inherit version;
+  version = "1.3.1";
 
   src = fetchurl {
     url = "https://archive.mozilla.org/pub/opus/opus-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libopusenc/default.nix b/pkgs/development/libraries/libopusenc/default.nix
index c2d77185e692..3cb14a2ea99e 100644
--- a/pkgs/development/libraries/libopusenc/default.nix
+++ b/pkgs/development/libraries/libopusenc/default.nix
@@ -1,11 +1,8 @@
 { lib, stdenv, fetchurl, pkg-config, libopus }:
 
-let
-  version = "0.2.1";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libopusenc";
-  inherit version;
+  version = "0.2.1";
 
   src = fetchurl {
     url = "https://archive.mozilla.org/pub/opus/libopusenc-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libossp-uuid/default.nix b/pkgs/development/libraries/libossp-uuid/default.nix
index 824dac3a2f56..a283df1bbaea 100644
--- a/pkgs/development/libraries/libossp-uuid/default.nix
+++ b/pkgs/development/libraries/libossp-uuid/default.nix
@@ -1,10 +1,8 @@
 {lib, stdenv, fetchurl}:
 
-let version = "1.6.2"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libossp-uuid";
-  inherit version;
+  version = "1.6.2";
 
   src = fetchurl {
     url = "ftp://ftp.ossp.org/pkg/lib/uuid/uuid-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libspatialindex/default.nix b/pkgs/development/libraries/libspatialindex/default.nix
index 4c778fbd6902..2081650f90a9 100644
--- a/pkgs/development/libraries/libspatialindex/default.nix
+++ b/pkgs/development/libraries/libspatialindex/default.nix
@@ -1,10 +1,8 @@
 { lib, stdenv, fetchurl }:
 
-let version = "1.8.5"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libspatialindex";
-  inherit version;
+  version = "1.8.5";
 
   src = fetchurl {
     url = "https://download.osgeo.org/libspatialindex/spatialindex-src-${version}.tar.gz";
diff --git a/pkgs/development/libraries/libxc/default.nix b/pkgs/development/libraries/libxc/default.nix
index 95ce2406223c..0680e4b832ce 100644
--- a/pkgs/development/libraries/libxc/default.nix
+++ b/pkgs/development/libraries/libxc/default.nix
@@ -1,11 +1,8 @@
 { lib, stdenv, fetchFromGitLab, cmake, gfortran, perl }:
 
-let
-  version = "5.1.5";
-
-in stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "libxc";
-  inherit version;
+  version = "5.1.5";
 
   src = fetchFromGitLab {
     owner = "libxc";
diff --git a/pkgs/development/libraries/libzmf/default.nix b/pkgs/development/libraries/libzmf/default.nix
index f71b6d0c0b97..7965c934df3e 100644
--- a/pkgs/development/libraries/libzmf/default.nix
+++ b/pkgs/development/libraries/libzmf/default.nix
@@ -14,7 +14,6 @@ stdenv.mkDerivation rec {
   configureFlags = [ "--disable-werror" ];
 
   meta = {
-    inherit version;
     description = "A library that parses the file format of Zoner Callisto/Draw documents";
     license = lib.licenses.mpl20;
     maintainers = [lib.maintainers.raskin];
diff --git a/pkgs/development/libraries/phash/default.nix b/pkgs/development/libraries/phash/default.nix
index 250089c30b1c..8d3f3e987023 100644
--- a/pkgs/development/libraries/phash/default.nix
+++ b/pkgs/development/libraries/phash/default.nix
@@ -25,7 +25,6 @@ stdenv.mkDerivation rec {
   };
 
   meta = with lib; {
-    inherit version;
     description = "Compute the perceptual hash of an image";
     license = licenses.gpl3;
     maintainers = [maintainers.imalsogreg];
diff --git a/pkgs/development/libraries/spandsp/default.nix b/pkgs/development/libraries/spandsp/default.nix
index 85a3059f27bc..240c86534335 100644
--- a/pkgs/development/libraries/spandsp/default.nix
+++ b/pkgs/development/libraries/spandsp/default.nix
@@ -17,7 +17,6 @@ stdenv.mkDerivation rec {
     maintainers = with lib.maintainers; [raskin];
     license = lib.licenses.gpl2;
     downloadPage = "http://www.soft-switch.org/downloads/spandsp/";
-    inherit version;
     updateWalker = true;
   };
 }
diff --git a/pkgs/development/tools/analysis/rizin/default.nix b/pkgs/development/tools/analysis/rizin/default.nix
index 4e9543ef371d..ff7717312f87 100644
--- a/pkgs/development/tools/analysis/rizin/default.nix
+++ b/pkgs/development/tools/analysis/rizin/default.nix
@@ -77,6 +77,5 @@ stdenv.mkDerivation rec {
     license = lib.licenses.gpl3Plus;
     maintainers = with lib.maintainers; [ raskin makefu mic92 ];
     platforms = with lib.platforms; linux;
-    inherit version;
   };
 }
diff --git a/pkgs/development/tools/build-managers/apache-ant/1.9.nix b/pkgs/development/tools/build-managers/apache-ant/1.9.nix
index 7ae24c69148c..80f8f1f886c2 100644
--- a/pkgs/development/tools/build-managers/apache-ant/1.9.nix
+++ b/pkgs/development/tools/build-managers/apache-ant/1.9.nix
@@ -1,10 +1,8 @@
 { fetchurl, lib, stdenv, coreutils, makeWrapper }:
 
-let version = "1.9.16"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "ant";
-  inherit version;
+  version = "1.9.16";
 
   nativeBuildInputs = [ makeWrapper ];
 
diff --git a/pkgs/development/tools/build-managers/apache-ant/default.nix b/pkgs/development/tools/build-managers/apache-ant/default.nix
index 6ff91a4e5a6d..7c05fcf60a37 100644
--- a/pkgs/development/tools/build-managers/apache-ant/default.nix
+++ b/pkgs/development/tools/build-managers/apache-ant/default.nix
@@ -1,10 +1,8 @@
 { fetchurl, lib, stdenv, coreutils, makeWrapper }:
 
-let version = "1.10.11"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "ant";
-  inherit version;
+  version = "1.10.11";
 
   nativeBuildInputs = [ makeWrapper ];
 
diff --git a/pkgs/development/tools/build-managers/gnumake/4.2/default.nix b/pkgs/development/tools/build-managers/gnumake/4.2/default.nix
index 387650e85ab7..5d0a91273319 100644
--- a/pkgs/development/tools/build-managers/gnumake/4.2/default.nix
+++ b/pkgs/development/tools/build-managers/gnumake/4.2/default.nix
@@ -2,12 +2,9 @@
 
 assert guileSupport -> ( pkg-config != null && guile != null );
 
-let
-  version = "4.2.1";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "gnumake";
-  inherit version;
+  version = "4.2.1";
 
   src = fetchurl {
     url = "mirror://gnu/make/make-${version}.tar.bz2";
diff --git a/pkgs/development/tools/build-managers/gnumake/default.nix b/pkgs/development/tools/build-managers/gnumake/default.nix
index 8e0095bb819e..b6d5d8e15486 100644
--- a/pkgs/development/tools/build-managers/gnumake/default.nix
+++ b/pkgs/development/tools/build-managers/gnumake/default.nix
@@ -1,11 +1,8 @@
 { lib, stdenv, fetchurl, guileSupport ? false, pkg-config, guile }:
 
-let
-  version = "4.3";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "gnumake";
-  inherit version;
+  version = "4.3";
 
   src = fetchurl {
     url = "mirror://gnu/make/make-${version}.tar.gz";
diff --git a/pkgs/development/tools/build-managers/rebar/default.nix b/pkgs/development/tools/build-managers/rebar/default.nix
index 30c55dbca373..c6e74a8ebb2c 100644
--- a/pkgs/development/tools/build-managers/rebar/default.nix
+++ b/pkgs/development/tools/build-managers/rebar/default.nix
@@ -1,12 +1,8 @@
 { lib, stdenv, fetchurl, erlang }:
 
-
-let
-  version = "2.6.4";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "rebar";
-  inherit version;
+  version = "2.6.4";
 
   src = fetchurl {
     url = "https://github.com/rebar/rebar/archive/${version}.tar.gz";
diff --git a/pkgs/development/tools/continuous-integration/drone-cli/default.nix b/pkgs/development/tools/continuous-integration/drone-cli/default.nix
index 245aeeb4351b..4534298d395e 100644
--- a/pkgs/development/tools/continuous-integration/drone-cli/default.nix
+++ b/pkgs/development/tools/continuous-integration/drone-cli/default.nix
@@ -1,8 +1,7 @@
 { lib, fetchFromGitHub, buildGoModule }:
 
-let version = "1.3.0";
-in buildGoModule rec {
-  inherit version;
+buildGoModule rec {
+  version = "1.3.0";
   pname = "drone-cli";
   revision = "v${version}";
 
diff --git a/pkgs/development/tools/database/squirrel-sql/default.nix b/pkgs/development/tools/database/squirrel-sql/default.nix
index 5aca6d55bc81..4363ec430957 100644
--- a/pkgs/development/tools/database/squirrel-sql/default.nix
+++ b/pkgs/development/tools/database/squirrel-sql/default.nix
@@ -4,11 +4,9 @@
 , jre
 , drivers ? []
 }:
-let
-  version = "4.1.0";
-in stdenv.mkDerivation rec {
+stdenv.mkDerivation rec {
   pname = "squirrel-sql";
-  inherit version;
+  version = "4.1.0";
 
   src = fetchurl {
     url = "mirror://sourceforge/project/squirrel-sql/1-stable/${version}-plainzip/squirrelsql-${version}-standard.zip";
diff --git a/pkgs/development/tools/flyway/default.nix b/pkgs/development/tools/flyway/default.nix
index f581806433f6..4679c6aa0523 100644
--- a/pkgs/development/tools/flyway/default.nix
+++ b/pkgs/development/tools/flyway/default.nix
@@ -1,39 +1,36 @@
 { lib, stdenv, fetchurl, jre_headless, makeWrapper }:
-  let
-    version = "7.5.4";
-  in
-    stdenv.mkDerivation {
-      pname = "flyway";
-      inherit version;
-      src = fetchurl {
-        url = "https://repo1.maven.org/maven2/org/flywaydb/flyway-commandline/${version}/flyway-commandline-${version}.tar.gz";
-        sha256 = "sha256-WU8j1NSf2KfA/HJWFtMLOZ3t5nxW4sU713e6qEEhZ0I=";
-      };
-      nativeBuildInputs = [ makeWrapper ];
-      dontBuild = true;
-      dontStrip = true;
-      installPhase = ''
-        mkdir -p $out/bin $out/share/flyway
-        cp -r sql jars drivers conf $out/share/flyway
-        install -Dt $out/share/flyway/lib lib/community/*.jar lib/*.jar
-        makeWrapper "${jre_headless}/bin/java" $out/bin/flyway \
-          --add-flags "-Djava.security.egd=file:/dev/../dev/urandom" \
-          --add-flags "-classpath '$out/share/flyway/lib/*:$out/share/flyway/drivers/*'" \
-          --add-flags "org.flywaydb.commandline.Main" \
-          --add-flags "-jarDirs='$out/share/flyway/jars'"
-      '';
-      meta = with lib; {
-        description = "Evolve your Database Schema easily and reliably across all your instances";
-        longDescription = ''
-          The Flyway command-line tool is a standalone Flyway distribution.
-          It is primarily meant for users who wish to migrate their database from the command-line
-          without having to integrate Flyway into their applications nor having to install a build tool.
+stdenv.mkDerivation rec{
+  pname = "flyway";
+  version = "7.5.4";
+  src = fetchurl {
+    url = "https://repo1.maven.org/maven2/org/flywaydb/flyway-commandline/${version}/flyway-commandline-${version}.tar.gz";
+    sha256 = "sha256-WU8j1NSf2KfA/HJWFtMLOZ3t5nxW4sU713e6qEEhZ0I=";
+  };
+  nativeBuildInputs = [ makeWrapper ];
+  dontBuild = true;
+  dontStrip = true;
+  installPhase = ''
+    mkdir -p $out/bin $out/share/flyway
+    cp -r sql jars drivers conf $out/share/flyway
+    install -Dt $out/share/flyway/lib lib/community/*.jar lib/*.jar
+    makeWrapper "${jre_headless}/bin/java" $out/bin/flyway \
+      --add-flags "-Djava.security.egd=file:/dev/../dev/urandom" \
+      --add-flags "-classpath '$out/share/flyway/lib/*:$out/share/flyway/drivers/*'" \
+      --add-flags "org.flywaydb.commandline.Main" \
+      --add-flags "-jarDirs='$out/share/flyway/jars'"
+  '';
+  meta = with lib; {
+    description = "Evolve your Database Schema easily and reliably across all your instances";
+    longDescription = ''
+      The Flyway command-line tool is a standalone Flyway distribution.
+      It is primarily meant for users who wish to migrate their database from the command-line
+      without having to integrate Flyway into their applications nor having to install a build tool.
 
-          This package is only the Community Edition of the Flyway command-line tool.
-        '';
-        homepage = "https://flywaydb.org/";
-        license = licenses.asl20;
-        platforms = platforms.unix;
-        maintainers = [ maintainers.cmcdragonkai ];
-      };
-    }
+      This package is only the Community Edition of the Flyway command-line tool.
+    '';
+    homepage = "https://flywaydb.org/";
+    license = licenses.asl20;
+    platforms = platforms.unix;
+    maintainers = [ maintainers.cmcdragonkai ];
+  };
+}
diff --git a/pkgs/development/tools/java/fastjar/default.nix b/pkgs/development/tools/java/fastjar/default.nix
index 52211e302dd9..c81df42edb11 100644
--- a/pkgs/development/tools/java/fastjar/default.nix
+++ b/pkgs/development/tools/java/fastjar/default.nix
@@ -1,32 +1,31 @@
 { fetchurl, lib, stdenv, zlib }:
 
-let version = "0.98"; in
-  stdenv.mkDerivation {
-    pname = "fastjar";
-    inherit version;
+stdenv.mkDerivation rec {
+  pname = "fastjar";
+  version = "0.98";
 
-    src = fetchurl {
-      url = "https://download.savannah.gnu.org/releases/fastjar/fastjar-${version}.tar.gz";
-      sha256 = "0iginbz2m15hcsa3x4y7v3mhk54gr1r7m3ghx0pg4n46vv2snmpi";
-    };
+  src = fetchurl {
+    url = "https://download.savannah.gnu.org/releases/fastjar/fastjar-${version}.tar.gz";
+    sha256 = "0iginbz2m15hcsa3x4y7v3mhk54gr1r7m3ghx0pg4n46vv2snmpi";
+  };
 
-    buildInputs = [ zlib ];
+  buildInputs = [ zlib ];
 
-    doCheck = true;
+  doCheck = true;
 
-    meta = {
-      description = "Fast Java archiver written in C";
+  meta = {
+    description = "Fast Java archiver written in C";
 
-      longDescription = ''
-        Fastjar is a version of Sun's `jar' utility, written entirely in C, and
-        therefore quite a bit faster.  Fastjar can be up to 100x faster than
-        the stock `jar' program running without a JIT.
-      '';
+    longDescription = ''
+      Fastjar is a version of Sun's `jar' utility, written entirely in C, and
+      therefore quite a bit faster.  Fastjar can be up to 100x faster than
+      the stock `jar' program running without a JIT.
+    '';
 
-      homepage = "https://savannah.nongnu.org/projects/fastjar/";
+    homepage = "https://savannah.nongnu.org/projects/fastjar/";
 
-      license = lib.licenses.gpl2Plus;
-      platforms = lib.platforms.linux;
-      maintainers = [ ];
-    };
-  }
+    license = lib.licenses.gpl2Plus;
+    platforms = lib.platforms.linux;
+    maintainers = [ ];
+  };
+}
diff --git a/pkgs/development/tools/jq/default.nix b/pkgs/development/tools/jq/default.nix
index 39819db47def..feeb22e1d441 100644
--- a/pkgs/development/tools/jq/default.nix
+++ b/pkgs/development/tools/jq/default.nix
@@ -66,6 +66,5 @@ stdenv.mkDerivation rec {
     platforms = with platforms; linux ++ darwin;
     downloadPage = "http://stedolan.github.io/jq/download/";
     updateWalker = true;
-    inherit version;
   };
 }
diff --git a/pkgs/development/tools/minizinc/default.nix b/pkgs/development/tools/minizinc/default.nix
index c1e0a356df35..06a6bd3dfd54 100644
--- a/pkgs/development/tools/minizinc/default.nix
+++ b/pkgs/development/tools/minizinc/default.nix
@@ -1,10 +1,7 @@
 { lib, stdenv, fetchFromGitHub, cmake, flex, bison }:
-let
-  version = "2.5.5";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "minizinc";
-  inherit version;
+  version = "2.5.5";
 
   nativeBuildInputs = [ cmake flex bison ];
 
diff --git a/pkgs/development/tools/minizinc/ide.nix b/pkgs/development/tools/minizinc/ide.nix
index a1ce9d0a6960..ef7dcb353215 100644
--- a/pkgs/development/tools/minizinc/ide.nix
+++ b/pkgs/development/tools/minizinc/ide.nix
@@ -1,10 +1,7 @@
 { lib, mkDerivation, fetchFromGitHub, qtbase, qtwebengine, qtwebkit, qmake, minizinc }:
-let
-  version = "2.5.3";
-in
-mkDerivation {
+mkDerivation rec {
   pname = "minizinc-ide";
-  inherit version;
+  version = "2.5.3";
 
   nativeBuildInputs = [ qmake ];
   buildInputs = [ qtbase qtwebengine qtwebkit ];
diff --git a/pkgs/development/tools/misc/dfu-programmer/default.nix b/pkgs/development/tools/misc/dfu-programmer/default.nix
index f0a3a9b76006..062f68c83438 100644
--- a/pkgs/development/tools/misc/dfu-programmer/default.nix
+++ b/pkgs/development/tools/misc/dfu-programmer/default.nix
@@ -1,10 +1,7 @@
 { lib, stdenv, fetchurl, libusb-compat-0_1 }:
-let
-  version = "0.7.2";
-in
 stdenv.mkDerivation rec {
   pname = "dfu-programmer";
-  inherit version;
+  version = "0.7.2";
 
   buildInputs = [ libusb-compat-0_1 ];
 
diff --git a/pkgs/development/tools/misc/luarocks/default.nix b/pkgs/development/tools/misc/luarocks/default.nix
index d4f2ec4ded98..f3ec4b4d7a43 100644
--- a/pkgs/development/tools/misc/luarocks/default.nix
+++ b/pkgs/development/tools/misc/luarocks/default.nix
@@ -68,7 +68,6 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with lib; {
-    inherit version;
     description = "A package manager for Lua";
     license = licenses.mit ;
     maintainers = with maintainers; [raskin teto];
diff --git a/pkgs/development/tools/misc/nixbang/default.nix b/pkgs/development/tools/misc/nixbang/default.nix
index 468623241bfd..bcddf4479eb0 100644
--- a/pkgs/development/tools/misc/nixbang/default.nix
+++ b/pkgs/development/tools/misc/nixbang/default.nix
@@ -1,9 +1,8 @@
 { lib, pythonPackages, fetchFromGitHub }:
 
-let version = "0.1.2"; in
-pythonPackages.buildPythonApplication {
+pythonPackages.buildPythonApplication rec {
   pname = "nixbang";
-  inherit version;
+  version = "0.1.2";
   namePrefix = "";
 
   src = fetchFromGitHub {
diff --git a/pkgs/development/tools/misc/prelink/default.nix b/pkgs/development/tools/misc/prelink/default.nix
index 63fc7c8e64a5..2fbee4ca5f52 100644
--- a/pkgs/development/tools/misc/prelink/default.nix
+++ b/pkgs/development/tools/misc/prelink/default.nix
@@ -1,11 +1,8 @@
 { lib, stdenv, fetchurl, libelf }:
 
-let
-  version = "20130503";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "prelink";
-  inherit version;
+  version = "20130503";
 
   buildInputs = [
     libelf stdenv.cc.libc (lib.getOutput "static" stdenv.cc.libc)
diff --git a/pkgs/development/tools/ocaml/obuild/default.nix b/pkgs/development/tools/ocaml/obuild/default.nix
index e31334000da0..a380dbff81f1 100644
--- a/pkgs/development/tools/ocaml/obuild/default.nix
+++ b/pkgs/development/tools/ocaml/obuild/default.nix
@@ -1,10 +1,8 @@
 { lib, stdenv, fetchzip, ocaml }:
 
-let version = "0.1.10"; in
-
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "obuild";
-  inherit version;
+  version = "0.1.10";
 
   src = fetchzip {
     url = "https://github.com/ocaml-obuild/obuild/archive/obuild-v${version}.tar.gz";
diff --git a/pkgs/development/tools/ocaml/ocamlbuild/default.nix b/pkgs/development/tools/ocaml/ocamlbuild/default.nix
index c74794b35c95..926838ede545 100644
--- a/pkgs/development/tools/ocaml/ocamlbuild/default.nix
+++ b/pkgs/development/tools/ocaml/ocamlbuild/default.nix
@@ -1,10 +1,7 @@
 { lib, stdenv, fetchFromGitHub, ocaml, findlib }:
-let
-  version = "0.14.0";
-in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   name = "ocamlbuild-${version}";
-  inherit version;
+  version = "0.14.0";
 
   src = fetchFromGitHub {
     owner = "ocaml";
diff --git a/pkgs/development/tools/parsing/bisonc++/default.nix b/pkgs/development/tools/parsing/bisonc++/default.nix
index 5710500a18f7..5a38c6679eb2 100644
--- a/pkgs/development/tools/parsing/bisonc++/default.nix
+++ b/pkgs/development/tools/parsing/bisonc++/default.nix
@@ -46,7 +46,6 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with lib; {
-    inherit version;
     description = "A parser generator like bison, but it generates C++ code";
     license = licenses.gpl2Plus;
     maintainers = with maintainers; [ raskin ];
diff --git a/pkgs/development/tools/spirv-tools/default.nix b/pkgs/development/tools/spirv-tools/default.nix
index 57f04b00c0d2..2cf3a2c801b1 100644
--- a/pkgs/development/tools/spirv-tools/default.nix
+++ b/pkgs/development/tools/spirv-tools/default.nix
@@ -1,12 +1,9 @@
 { lib, stdenv, fetchFromGitHub, cmake, python3, spirv-headers }:
-let
-  # Update spirv-headers rev in lockstep according to DEPs file
-  version = "2020.2";
-in
 
 stdenv.mkDerivation rec {
   pname = "spirv-tools";
-  inherit version;
+  # Update spirv-headers rev in lockstep according to DEPs file
+  version = "2020.2";
 
   src = fetchFromGitHub {
     owner = "KhronosGroup";
diff --git a/pkgs/tools/filesystems/fuse-7z-ng/default.nix b/pkgs/tools/filesystems/fuse-7z-ng/default.nix
index 8a0671957c35..0149071ab0d0 100644
--- a/pkgs/tools/filesystems/fuse-7z-ng/default.nix
+++ b/pkgs/tools/filesystems/fuse-7z-ng/default.nix
@@ -25,7 +25,6 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with lib; {
-    inherit version;
     inherit (src.homepage);
     description = "A FUSE-based filesystem that uses the p7zip library";
     longDescription = ''
diff --git a/pkgs/tools/filesystems/jmtpfs/default.nix b/pkgs/tools/filesystems/jmtpfs/default.nix
index 8589abffc77d..2754d223a6ba 100644
--- a/pkgs/tools/filesystems/jmtpfs/default.nix
+++ b/pkgs/tools/filesystems/jmtpfs/default.nix
@@ -1,9 +1,8 @@
 { lib, stdenv, fetchFromGitHub, fetchpatch, pkg-config, file, fuse, libmtp }:
 
-let version = "0.5"; in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   pname = "jmtpfs";
-  inherit version;
+  version = "0.5";
 
   src = fetchFromGitHub {
     sha256 = "1pm68agkhrwgrplrfrnbwdcvx5lrivdmqw8pb5gdmm3xppnryji1";
diff --git a/pkgs/tools/filesystems/reiser4progs/default.nix b/pkgs/tools/filesystems/reiser4progs/default.nix
index 961a286729a8..f833d562972a 100644
--- a/pkgs/tools/filesystems/reiser4progs/default.nix
+++ b/pkgs/tools/filesystems/reiser4progs/default.nix
@@ -1,9 +1,8 @@
 {lib, stdenv, fetchurl, libaal}:
 
-let version = "2.0.4"; in
 stdenv.mkDerivation rec {
   pname = "reiser4progs";
-  inherit version;
+  version = "2.0.4";
 
   src = fetchurl {
     url = "mirror://sourceforge/reiser4/reiser4-utils/${pname}-${version}.tar.gz";
diff --git a/pkgs/tools/filesystems/reiserfsprogs/default.nix b/pkgs/tools/filesystems/reiserfsprogs/default.nix
index dc97cdb652e2..c6583410ff3c 100644
--- a/pkgs/tools/filesystems/reiserfsprogs/default.nix
+++ b/pkgs/tools/filesystems/reiserfsprogs/default.nix
@@ -1,9 +1,8 @@
 { lib, stdenv, fetchurl, libuuid, autoreconfHook }:
 
-let version = "3.6.24"; in
 stdenv.mkDerivation rec {
   pname = "reiserfsprogs";
-  inherit version;
+  version = "3.6.24";
 
   src = fetchurl {
     url = "https://www.kernel.org/pub/linux/kernel/people/jeffm/reiserfsprogs/v${version}/${pname}-${version}.tar.xz";
diff --git a/pkgs/tools/filesystems/zfstools/default.nix b/pkgs/tools/filesystems/zfstools/default.nix
index ecc4b1184867..feb5b23df52a 100644
--- a/pkgs/tools/filesystems/zfstools/default.nix
+++ b/pkgs/tools/filesystems/zfstools/default.nix
@@ -1,9 +1,8 @@
 { lib, stdenv, fetchFromGitHub, ruby, zfs }:
 
-let version = "0.3.6"; in
 stdenv.mkDerivation rec {
   pname = "zfstools";
-  inherit version;
+  version = "0.3.6";
 
   src = fetchFromGitHub {
     sha256 = "16lvw3xbmxp2pr8nixqn7lf4504zaaxvbbdnjkv4dggwd4lsdjyg";