treewide: rename version attributes

As suggested in https://github.com/NixOS/nixpkgs/pull/39416#discussion_r183845745
the versioning attributes in `lib` should be consistent to
`nixos/version` which implicates the following changes:

* `lib.trivial.version` -> `lib.trivial.release`
* `lib.trivial.suffix` -> `lib.trivial.versionSuffix`
* `lib.nixpkgsVersion` -> `lib.version`

As `lib.nixpkgsVersion` is referenced several times in `NixOS/nixpkgs`,
`NixOS/nix` and probably several user's setups. As the rename will cause
a notable impact it's better to keep `lib.nixpkgsVersion` as alias with
a warning yielded by `builtins.trace`.

doc/Makefile

@@ -64,7 +64,7 @@ manual-full.xml: ${MD_TARGETS} .version *.xml
 
 .version:
 	nix-instantiate --eval \
-		-E '(import ../lib).nixpkgsVersion' > .version
+		-E '(import ../lib).version' > .version
 
 %.section.xml: %.section.md
 	pandoc $^ -w docbook+smart \

doc/default.nix

@@ -30,7 +30,7 @@ pkgs.stdenv.mkDerivation {
   ];
 
   postPatch = ''
-    echo ${lib.nixpkgsVersion} > .version
+    echo ${lib.version} > .version
   '';
 
   installPhase = ''

lib/default.nix

@@ -58,7 +58,7 @@ let
       replaceStrings seq stringLength sub substring tail;
     inherit (trivial) id const concat or and boolToString mergeAttrs
       flip mapNullable inNixShell min max importJSON warn info
-      nixpkgsVersion mod compare splitByAndCompare
+      nixpkgsVersion version mod compare splitByAndCompare
       functionArgs setFunctionArgs isFunction;
 
     inherit (fixedPoints) fix fix' extends composeExtensions

lib/trivial.nix

@@ -58,12 +58,14 @@ rec {
 
   inherit (lib.strings) fileContents;
 
-  version = fileContents ../.version;
+  release = fileContents ../.version;
-  suffix = let suffixFile = ../.version-suffix; in
+  versionSuffix = let suffixFile = ../.version-suffix; in
     if pathExists suffixFile then fileContents suffixFile else "pre-git";
 
   # Return the Nixpkgs version number.
-  nixpkgsVersion = version + suffix;
+  version = release + versionSuffix;
+
+  nixpkgsVersion = builtins.trace "`lib.nixpkgsVersion` is deprecated, use `lib.version` instead!" version;
 
   # Whether we're being called by nix-shell.
   inNixShell = builtins.getEnv "IN_NIX_SHELL" != "";

nixos/doc/manual/release-notes/rl-1809.xml

@@ -123,6 +123,11 @@ following incompatible changes:</para>
       <literal>lib.traceCallXml</literal> has been deprecated. Please complain
       if you use the function regularly.
     </para>
+    <para>
+      The attribute <literal>lib.nixpkgsVersion</literal> has been deprecated in favor of
+      <literal>lib.version</literal>. Please refer to the discussion in
+      <link xlink:href="https://github.com/NixOS/nixpkgs/pull/39416#discussion_r183845745">NixOS/nixpkgs#39416</link> for further reference.
+    </para>
   </listitem>
 </itemizedlist>
 

nixos/maintainers/scripts/ec2/create-amis.sh

@@ -6,7 +6,7 @@
 set -e
 set -o pipefail
 
-version=$(nix-instantiate --eval --strict '<nixpkgs>' -A lib.nixpkgsVersion | sed s/'"'//g)
+version=$(nix-instantiate --eval --strict '<nixpkgs>' -A lib.version | sed s/'"'//g)
 major=${version:0:5}
 echo "NixOS version is $version ($major)"
 

nixos/modules/misc/version.nix

@@ -23,14 +23,14 @@ in
     nixos.release = mkOption {
       readOnly = true;
       type = types.str;
-      default = trivial.version;
+      default = trivial.release;
       description = "The NixOS release (e.g. <literal>16.03</literal>).";
     };
 
     nixos.versionSuffix = mkOption {
       internal = true;
       type = types.str;
-      default = trivial.suffix;
+      default = trivial.versionSuffix;
       description = "The NixOS version suffix (e.g. <literal>1160.f2d4ee1</literal>).";
     };
 

pkgs/tools/system/osquery/default.nix

@@ -24,7 +24,7 @@ stdenv.mkDerivation rec {
 
   # this is what `osquery --help` will show as the version.
   OSQUERY_BUILD_VERSION = version;
-  OSQUERY_PLATFORM = "nixos;${stdenv.lib.nixpkgsVersion}";
+  OSQUERY_PLATFORM = "nixos;${stdenv.lib.version}";
 
   src = fetchFromGitHub {
     owner = "facebook";