diff --git a/pkgs/build-support/src-only/default.nix b/pkgs/build-support/src-only/default.nix
index a93b3648090..c721fdf40c6 100644
--- a/pkgs/build-support/src-only/default.nix
+++ b/pkgs/build-support/src-only/default.nix
@@ -1,6 +1,31 @@
-{stdenv, name, src, patches ? [], buildInputs ? [], ...}: 
+{ stdenv }@orig:
+# srcOnly is a utility builder that only fetches and unpacks the given `src`,
+# maybe pathings it in the process with the optional `patches` and
+# `buildInputs` attributes.
+#
+# It can be invoked directly, or be used to wrap an existing derivation. Eg:
+#
+# > srcOnly pkgs.hello
+#
+{ name
+, src
+, stdenv ? orig.stdenv
+, patches ? []
+, # deprecated, use the nativeBuildInputs
+  buildInputs ? []
+, # used to pass extra unpackers
+  nativeBuildInputs ? []
+, # needed when passing an existing derivation
+  ...
+}:
 stdenv.mkDerivation {
-  inherit src buildInputs patches name;
+  inherit
+    buildInputs
+    name
+    nativeBuildInputs
+    patches
+    src
+    ;
   installPhase = "cp -r . $out";
   phases = ["unpackPhase" "patchPhase" "installPhase"];
 }
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 97cb7e8f1e1..49ab4d06c10 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -450,7 +450,7 @@ in
 
   singularity-tools = callPackage ../build-support/singularity-tools { };
 
-  srcOnly = args: callPackage ../build-support/src-only args;
+  srcOnly = callPackage ../build-support/src-only { };
 
   substituteAll = callPackage ../build-support/substitute/substitute-all.nix { };