From 69353cef31aba396015c342c3e4e7a52f89ea683 Mon Sep 17 00:00:00 2001
From: Martin Weinelt <hexa@darmstadt.ccc.de>
Date: Thu, 25 Jun 2026 13:43:14 +0200
Subject: [PATCH] nixos/channel: add zstd flavored nixexprs tarball

This can significantly speed up consumption of nixexprs because zstd
decompress is generally 10x faster than xz.
---
 nixos/lib/make-channel.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/nixos/lib/make-channel.nix b/nixos/lib/make-channel.nix
index e366006e908c..f4fca9bf2f7b 100644
--- a/nixos/lib/make-channel.nix
+++ b/nixos/lib/make-channel.nix
@@ -18,7 +18,10 @@ pkgs.releaseTools.makeSourceTarball {
   officialRelease = false; # FIXME: fix this in makeSourceTarball
   inherit version versionSuffix;
 
-  buildInputs = [ pkgs.nix ];
+  buildInputs = with pkgs; [
+    nix
+    zstd
+  ];
 
   distPhase = ''
     rm -rf .git
@@ -33,5 +36,10 @@ pkgs.releaseTools.makeSourceTarball {
     cd ..
     chmod -R u+w $releaseName
     tar cfJ $out/tarballs/$releaseName.tar.xz $releaseName
+    tar \
+      --create \
+      --file="$out/tarballs/$releaseName.tar.zst" \
+      --use-compress-program="zstd -19 -T$NIX_BUILD_CORES" \
+      $releaseName
   '';
 }