fix_nixos_toolchain.patch

diff --git a/MODULE.bazel.lock b/MODULE.bazel.lock
index 2923d8acb2..2d0771949a 100644
--- a/MODULE.bazel.lock
+++ b/MODULE.bazel.lock
@@ -13694,7 +13694,7 @@
     },
     "@@toolchains_llvm~//toolchain/extensions:llvm.bzl%llvm": {
       "general": {
-        "bzlTransitiveDigest": "i2QyNjD/qcSQlxaKhQjSN1uw8mm+ZusH07AWV6RnyQU=",
+        "bzlTransitiveDigest": "M4HHCg9Yz0gvoVQnnqi5wlJY1oxlqaj4Khqr94ZjtXo=",
         "usagesDigest": "VkFLWYT36e0E0cIEzYI8Sea6Ww4GK5ceD6oJqC8Xof8=",
         "recordedFileInputs": {},
         "recordedDirentsInputs": {},
diff --git a/third_party/rust/rust.MODULE.bazel b/third_party/rust/rust.MODULE.bazel
index c787accbb1..59a4dbd7d4 100644
--- a/third_party/rust/rust.MODULE.bazel
+++ b/third_party/rust/rust.MODULE.bazel
@@ -15,6 +15,13 @@ single_version_override(
     ],
     version = "0.49.3",
 )
+single_version_override(
+    module_name = "toolchains_llvm",
+    patches = [
+        "//third_party/rust/patches:toolchains_llvm.add_nixos.patch",
+    ],
+    version = "1.1.2",
+)
 
 # Rust toolchain:
 rust = use_extension("@rules_rust//rust:extensions.bzl", "rust")
(python-venv) [12:09:45][pamaury@jamesBOND:/home/pamaury/project/opentitan]master$ git add third_party/rust/
patches/           rust.MODULE.bazel  target/            
(python-venv) [12:09:45][pamaury@jamesBOND:/home/pamaury/project/opentitan]master$ git add third_party/rust/patches/
rules_rust.bindgen_system_include.patch  toolchains_llvm.add_nixos.patch          
(python-venv) [12:09:45][pamaury@jamesBOND:/home/pamaury/project/opentitan]master$ git add third_party/rust/patches/toolchains_llvm.add_nixos.patch 
(python-venv) [12:09:54][pamaury@jamesBOND:/home/pamaury/project/opentitan]master$ git diff --staged
diff --git a/third_party/rust/patches/toolchains_llvm.add_nixos.patch b/third_party/rust/patches/toolchains_llvm.add_nixos.patch
new file mode 100644
index 0000000000..d66b84f6b1
--- /dev/null
+++ b/third_party/rust/patches/toolchains_llvm.add_nixos.patch
@@ -0,0 +1,13 @@
+diff --git a/toolchain/internal/release_name.bzl b/toolchain/internal/release_name.bzl
+index e3d4a54..ce0d193 100755
+--- toolchain/internal/release_name.bzl
++++ toolchain/internal/release_name.bzl
+@@ -177,6 +177,8 @@ def _linux(llvm_version, distname, version, arch):
+         os_name = "linux-gnueabihf"
+     elif distname in ["rhel", "ol", "almalinux"]:
+         os_name = _rhel_osname(arch, version, major_llvm_version, llvm_version)
++    elif distname == "nixos":
++        os_name = _ubuntu_osname(arch, "20.04", major_llvm_version, llvm_version)
+ 
+     if not os_name:
+         fail("Unsupported linux distribution and version: %s, %s" % (distname, version))