add sysroot lockfile update script then run it

pkgs/build-support/rust/sysroot/Cargo.lock

@@ -1,14 +1,21 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "alloc"
 version = "0.0.0"
-dependencies = ["compiler_builtins", "core"]
+dependencies = [
+ "compiler_builtins",
+ "core",
+]
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.32"
+version = "0.1.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7bc4ac2c824d2bfc612cba57708198547e9a26943af0632aff033e0693074d5c"
-dependencies = ["rustc-std-workspace-core"]
+checksum = "7cd0782e0a7da7598164153173e5a5d4d9b1da094473c98dce0ff91406112369"
+dependencies = [
+ "rustc-std-workspace-core",
+]
 
 [[package]]
 name = "core"
@@ -17,4 +24,6 @@ version = "0.0.0"
 [[package]]
 name = "rustc-std-workspace-core"
 version = "1.99.0"
-dependencies = ["core"]
+dependencies = [
+ "core",
+]

pkgs/build-support/rust/sysroot/cargo.py

@@ -2,7 +2,7 @@ import os
 import toml
 
 rust_src = os.environ['RUSTC_SRC']
-orig_cargo = os.environ['ORIG_CARGO']
+orig_cargo = os.environ['ORIG_CARGO'] if 'ORIG_CARGO' in os.environ else None
 
 base = {
   'package': {
@@ -33,6 +33,7 @@ base = {
   },
 }
 
+if orig_cargo is not None:
   with open(orig_cargo, 'r') as f:
     src = toml.loads(f.read())
     if 'profile' in src:

pkgs/build-support/rust/sysroot/default.nix

@@ -23,7 +23,7 @@ in rustPlatform.buildRustPackage {
 
   RUSTC_BOOTSTRAP = 1;
   __internal_dontAddSysroot = true;
-  cargoSha256 = "1l5z44dw5h7lbwmpjqax2g40cf4h27yai3wlj0p5di5v1xf25rng";
+  cargoSha256 = "0y6dqfhsgk00y3fv5bnjzk0s7i30nwqc1rp0xlrk83hkh80x81mw";
 
   doCheck = false;
 

pkgs/build-support/rust/sysroot/update-lockfile.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p python3 python3.pkgs.toml cargo
+
+set -e
+
+HERE=$(dirname "${BASH_SOURCE[0]}")
+NIXPKGS_ROOT="$HERE/../../../.."
+
+# https://unix.stackexchange.com/a/84980/390173
+tempdir=$(mktemp -d 2>/dev/null || mktemp -d -t 'update-lockfile')
+
+cd "$tempdir"
+nix-build -E "with import (/. + \"${NIXPKGS_ROOT}\") {}; pkgs.rustPlatform.rustcSrc.override { minimalContent = false; }"
+RUSTC_SRC="$(pwd)/result" python3 "$HERE/cargo.py"
+RUSTC_BOOTSTRAP=1 cargo build || echo "Build failure is expected. All that's needed is the lockfile."
+
+cp Cargo.lock "$HERE"
+
+rm -rf "$tempdir"
+
+