In reply to @quadradical:federated.nexus

error: builder for '/nix/store/ij147jszwkrf2ad1klcql0qrvadq2zys-glycin-loaders-aarch64-unknown-linux-gnu-1.2.3.drv' failed with exit code 1;
       last 6 log lines:
       > Running phase: unpackPhase
       > unpacking source archive /nix/store/ics3xr1jgfmagn18jax3h5nva7g5smys-glycin-1.2.3.tar.xz
       > source root is glycin-1.2.3
       > Executing cargoSetupPostUnpackHook
       > unpacking source archive
       > do not know how to unpack source archive
       For full logs, run 'nix log /nix/store/ij147jszwkrf2ad1klcql0qrvadq2zys-glycin-loaders-aarch64-unknown-linux-gnu-1.2.3.drv'.

In reply to @quadradical:federated.nexus
ill add it later

Try this in postPatch

cat >> .cargo/config.toml <<'EOF'
${rustPlatform.cargoSetupHook.cargoConfig}
EOF

diff --git a/pkgs/by-name/gl/glycin-loaders/package.nix b/pkgs/by-name/gl/glycin-loaders/package.nix
index 06bc12716d63..c0a237512fec 100644
--- a/pkgs/by-name/gl/glycin-loaders/package.nix
+++ b/pkgs/by-name/gl/glycin-loaders/package.nix
@@ -20,6 +20,7 @@
   ninja,
   pkg-config,
   rustc,
+  rustPlatform,
 }:
 
 stdenv.mkDerivation (finalAttrs: {
@@ -47,8 +48,11 @@ stdenv.mkDerivation (finalAttrs: {
     ninja
     pkg-config
     rustc
+    rustPlatform.cargoSetupHook
   ];
 
+  cargoVendorDir = "vendor";
+
   buildInputs = [
     gtk4 # for GdkTexture
     cairo
@@ -68,6 +72,13 @@ stdenv.mkDerivation (finalAttrs: {
 
   strictDeps = true;
 
+  postPatch = ''
+    substituteInPlace loaders/meson.build \
+      --replace-fail "cargo_target_dir / rust_target / loader," "cargo_target_dir / '${stdenv.hostPlatform.rust.cargoShortTarget}' / rust_target / loader,"
+  '';
+
+  env.CARGO_BUILD_TARGET = stdenv.hostPlatform.rust.rustcTargetSpec;
+
   passthru = {
     updateScript = gnome.updateScript {
       attrPath = "glycin-loaders";