Compiler-commit lookup for "Where Rust actually is in Windows 11" (hunterworks.software/teardowns/rust-in-windows-11)

Question: the Rust standard-library paths embedded in these binaries carry a rustc source-revision hash
(/rustc/<40 hex>/library/...). Does that revision exist in the upstream Rust repository, or anywhere public?

Ten distinct hashes were found across the current files (census-classified.tsv), the superseded builds in the
component store (winsxs-census.txt) and the DWriteCore bundled with WSL:

  hash                                      found in
  035286e292f0e487ce63a353282eeb01b7dd1b27  sudo.exe 1.0.1 (toolchain package rust.tools-x86_64-pc-windows-msvc.1.87.0-ms-20250722.10)
  d34f430ff80d42e354e722d8a62c378f98187773  DWriteCore.dll, App SDK 1.6.1 (inbox)
  c6bcfe6a6082b23fa084d9690fee241c23ee9d29  DWriteCore.dll, App SDK 1.7.1 (bundled with WSL)
  6a6eaca656978778f7c1c750ee0c3db87f8bffb2  DWriteCore.dll, App SDK 1.8.1 and 2.1.1 (inbox; rust.tools-...1.88.0-ms-20250913.5)
  82a24cd01a21d202b5234ec300f091d5b9863e87  CloudRecoveryDownloadTool.dll 0.2.717.0 (OS 26100.8115; rust.tools.stable-llvm-...1.90.0-ms-20251106.9)
  e47682180e2e1c6b545380f5ebe5fd54d1ec9916  CloudRecoveryDownloadTool.dll 0.3.28.0 (current; rust.tools.stable-llvm-...1.90.0-ms-20260302.10)
  0bcbc193706494af5b8e0d66669457db63fbdfbb  UdiApiClient.dll 0.2.789.0 and 0.4.45.0 (rust.tools.stable-llvm-...1.93.1-ms-20260416.7)
  fa6ff70ed0808ced4abe0e4dae135016bdcc8919  NarratorMCAT.dll, OS 26100.7705 build (rust.tools.stable-llvm-...1.88.0-ms-20250913.6)
  32dfec32535536bd884c46f0b69850be9f0b8d02  NarratorMCAT.dll, current (rust.tools.stable-utc-...1.95.0-ms-20260514.2)
  3e667cc525964eac87c7d4f68405a45b1196cd72  win32kbase_rs.sys, OS 26100.1301 build (later builds do not embed a hash)

Step 1: stable release manifests (rustc-stable-hashes.txt, static.rust-lang.org/dist/channel-rust-<version>.toml,
1.84.0 through 1.96.1, fetched 2026-09-03). None of the ten hashes matches any manifest's git_commit_hash.

Step 2: GitHub, unauthenticated REST API, 2026-09-04.

  a) Is the commit in rust-lang/rust?   GET https://api.github.com/repos/rust-lang/rust/commits/<hash>
     All ten -> HTTP 422 "No commit found for SHA: ...". A 422 from this endpoint means the object is not reachable
     in that repository.

  b) Is the commit in ANY public GitHub repository?   GET https://api.github.com/search/commits?q=hash:<hash>
     All ten -> total_count 0.

  c) Control, to show the endpoints find real upstream commits: the 1.87.0 release commit from the manifest,
     GET https://api.github.com/repos/rust-lang/rust/commits/17067e9ac6d7ecb70e50f92c1944e545188d2359
       -> found; committed 2025-05-09T20:37:37Z; "Auto merge of #140859 - pietroalbini:pa-stable, r=pietroalbini"

  d) Is 035286e2 an ancestor or descendant of the 1.87.0 tag?
     GET https://api.github.com/repos/rust-lang/rust/compare/1.87.0...035286e292f0e487ce63a353282eeb01b7dd1b27
       -> HTTP 404 (the commit is unknown to the repository, so no comparison is possible)

Reading: every compiler that built these files was built from a source revision that is not in rust-lang/rust and
not in any public repository GitHub indexes. Together with the package names
(rust.tools...-ms-<date>, installed under msrustup_home) and the Azure Artifacts crate feed, this is consistent with
Microsoft building its Rust toolchain from an internal fork or branch of the compiler. A hash cannot say what differs.

Limits: GitHub's commit search only covers public repositories it has indexed; a private fork is invisible by
definition. The 422 for rust-lang/rust is definitive for that repository.