versionCheckHook: use coreutils env; gzip: add passthru test

pkgs/by-name/ve/versionCheckHook/hook.sh

@@ -10,7 +10,7 @@ _handleCmdOutput(){
       done
     fi
 
-    versionOutput="$(env \
+    versionOutput="$(@envCommand@ \
         --chdir=/ \
         --argv0="$(basename "${command[0]}")" \
         "${envArgs[@]}" \

pkgs/by-name/ve/versionCheckHook/package.nix

@@ -1,12 +1,14 @@
 {
   lib,
   makeSetupHook,
+  coreutils,
 }:
 
 makeSetupHook {
   name = "version-check-hook";
   substitutions = {
     storeDir = builtins.storeDir;
+    envCommand = lib.getExe' coreutils "env"; # Cannot call it env, because it isn't an attrset of environment variables!
   };
   meta = {
     description = "Lookup for $version in the output of --help and --version";

pkgs/tools/compression/gzip/default.nix

@@ -5,6 +5,10 @@
   makeShellWrapper,
   updateAutotoolsGnuConfigScriptsHook,
   runtimeShellPackage,
+  # Tests
+  gzip,
+  less,
+  perl,
 }:
 
 # Note: this package is used for bootstrapping fetchurl, and thus
@@ -44,6 +48,12 @@ stdenv.mkDerivation rec {
     "ZLESS_PROG=zless"
   ];
 
+  nativeCheckInputs = [
+    less
+    perl
+  ];
+  doCheck = false;
+
   # Many gzip executables are shell scripts that depend upon other gzip
   # executables being in $PATH.  Rather than try to re-write all the
   # internal cross-references, just add $out/bin to PATH at the top of
@@ -60,6 +70,10 @@ stdenv.mkDerivation rec {
       --add-flags "\''${GZIP_NO_TIMESTAMPS:+-n}"
   '';
 
+  passthru = {
+    tests.makecheck = gzip.overrideAttrs { doCheck = true; };
+  };
+
   meta = {
     homepage = "https://www.gnu.org/software/gzip/";
     description = "GNU zip compression program";