diff --git a/pkgs/build-support/rust/sysroot/src.nix b/pkgs/build-support/rust/sysroot/src.nix
index e741326bd0d4..3d11b62dd315 100644
--- a/pkgs/build-support/rust/sysroot/src.nix
+++ b/pkgs/build-support/rust/sysroot/src.nix
@@ -5,7 +5,11 @@
 stdenv.mkDerivation {
   name = "cargo-src";
   preferLocalBuild = true;
-  phases = [ "installPhase" ];
+
+  unpackPhase = "true";
+  dontConfigure = true;
+  dontBuild = true;
+
   installPhase = ''
     export RUSTC_SRC=${rustPlatform.rustLibSrc.override { }}
   ''