sidecar: DXC's release check authenticates with GITHUB_TOKEN

.github/workflows/release.yml

@@ -284,8 +284,13 @@ jobs:
       - name: Fetch the pinned libav libraries
         run: python sidecar/ffrwd-wasm/fetch_av.py --target ${{ matrix.target }} --os ${{ runner.os }}
 
+      # On x86_64 Windows the build links DXC, whose build script asks the
+      # GitHub API about the release it downloads; the token keeps that
+      # request off the runner's unauthenticated rate limit.
       - name: Build wheel
         uses: PyO3/maturin-action@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           working-directory: sidecar/ffrwd-wasm
           command: build

sidecar/Cargo.toml

@@ -16,3 +16,8 @@ license = "Apache-2.0"
 # resolved.
 [patch.crates-io]
 wasmtime-wasi-nn = { path = "vendor/wasmtime-wasi-nn" }
+# mach-dxcompiler-rs, which links DXC on x86_64 MSVC, asks the GitHub API
+# whether its release is immutable. The vendored copy authenticates that
+# request with GITHUB_TOKEN when it is set, so a rate-limited runner does not
+# fail the build.
+mach-dxcompiler-rs = { path = "vendor/mach-dxcompiler-rs" }

sidecar/vendor/mach-dxcompiler-rs/.cargo_vcs_info.json

@@ -0,0 +1,6 @@
+{
+  "git": {
+    "sha1": "77b9a2f68c146d1cf45e52ed7e7ac2457be875d5"
+  },
+  "path_in_vcs": ""
+}

sidecar/vendor/mach-dxcompiler-rs/.gitignore

@@ -0,0 +1 @@
+/target

sidecar/vendor/mach-dxcompiler-rs/Cargo.toml

@@ -0,0 +1,55 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2021"
+name = "mach-dxcompiler-rs"
+version = "0.1.6+2026.09.16-48d5a66.1"
+build = "build.rs"
+autolib = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = """
+Prebuilt, statically-linked DXC.\r
+"""
+readme = "README.md"
+license = "MIT"
+repository = "https://github.com/DouglasDwyer/mach-dxcompiler-rs"
+
+[package.metadata."docs.rs"]
+features = ["cbindings"]
+
+[features]
+cbindings = ["dep:bindgen"]
+default = ["msvc_version_validation"]
+internal_update_targets = []
+msvc_version_validation = ["dep:cc"]
+
+[lib]
+name = "mach_dxcompiler_rs"
+path = "src/lib.rs"
+
+[build-dependencies.bindgen]
+version = "0.71.1"
+features = ["runtime"]
+optional = true
+default-features = false
+
+[build-dependencies.lhash]
+version = "1.1.0"
+features = ["sha256"]
+default-features = false
+
+[target.'cfg(target_env = "msvc")'.build-dependencies.cc]
+version = "1.2.3"
+optional = true