libmodsecurity: remove dependency on valgrind

[lopsided98]

Description of changes

valgrind is only supported on certain platforms (it notably lacks support for armv6l), so needs to be excluded as a dependency on unsupported platforms. In this case, it turns out that valgrind is not currently used at all, so I removed it entirely. libmodsecurity can optionally use valgrind to run tests, but we don't run the tests at all.

Note that I don't actually use libmodsecurity, but tengine depends on it and is evaluated as part of the nginx NixOS module even if it is not used: #147027 (comment)

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.05 Release Notes (or backporting 21.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[Izorkin]

Maybe this variant is better?

diff --git a/pkgs/tools/security/libmodsecurity/default.nix b/pkgs/tools/security/libmodsecurity/default.nix
index 4ba294e42f2..c22dc9f5321 100644
--- a/pkgs/tools/security/libmodsecurity/default.nix
+++ b/pkgs/tools/security/libmodsecurity/default.nix
@@ -1,7 +1,8 @@
 { lib, stdenv, fetchFromGitHub
 , autoreconfHook, bison, flex, pkg-config
 , curl, geoip, libmaxminddb, libxml2, lmdb, lua, pcre
-, ssdeep, valgrind, yajl
+, ssdeep, yajl
+, withValgrind ? false, valgrind
 , nixosTests
 }:

@@ -18,7 +19,7 @@ stdenv.mkDerivation rec {
   };

   nativeBuildInputs = [ autoreconfHook bison flex pkg-config ];
-  buildInputs = [ curl geoip libmaxminddb libxml2 lmdb lua pcre ssdeep valgrind yajl ];
+  buildInputs = [ curl geoip libmaxminddb libxml2 lmdb lua pcre ssdeep yajl ] ++ lib.optional withValgrind valgrind;

   outputs = [ "out" "dev" ];

[lopsided98]

Why? Valgrind is not currently used as far as I can tell. It certainly doesn't end up in the output closure.

If we ever wanted to run the tests, then it might make sense to do withValgrind ? lib.meta.availableOn stdenv.hostPlatform valgrind, but for now it is just unnecessarily increasing the build closure size.

[Izorkin]

I assumed that libmodsecurity uses valgrind for some specific operations. Or I'm wrong?

[SuperSandro2000]

valgrind is used for testing which we are not doing (but we should) and debugging which usually requires additional tools we don't install by default.