libc: wire the vendored fork into the fork machinery

The fork was an unmapped tree -- verify-fork-versions.sh reported
'libc NOT-MAPPED'. Register it properly so it is governed like every other
Cat 2 fork rather than sitting outside the checks:

- local/fork-upstream-map.toml: libc -> rust-lang/libc 0.2.189, snapshot
  mode (vendored from the registry, so its history is unrelated to
  upstream's), with the temporary status noted inline.
- verify-fork-versions.sh: src/unix/redox/mod.rs added to the declarative
  expected-differ list, so the content check keeps verifying the rest of
  the tree instead of being blanket-skipped.
- local/docs/VENDORED-LIBC-FORK.md: what the fork adds, the relibc source
  and evidence for every symbol, why the values come from relibc rather
  than Linux (Redox's idtype_t is c_int where glibc uses an enum), and a
  five-step retirement procedure.
- local/AGENTS.md: listed in the fork table, marked temporary.

Kept vendored for as long as it is required. The gap is upstream-
reportable and belongs in the libc crate.
This commit is contained in:
2026-08-03 18:08:24 +03:00
parent 88b4d06ec2
commit 09ba5201f4
4 changed files with 96 additions and 2 deletions
+1
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@@ -907,6 +907,7 @@ This rule applies to ALL Cat 2 fork crates:
| `libredox` | `local/sources/libredox/` | `path = "../../../../../local/sources/libredox"` |
| `redox-scheme` | `local/sources/redox-scheme/` | `path = "../../../../../local/sources/redox-scheme"` |
| `redoxfs` | `local/sources/redoxfs/` | `path = "../../../../../local/sources/redoxfs"` |
| `libc` | `local/sources/libc/` | via `[patch.crates-io]` in the rust workspace — **temporary**, see `local/docs/VENDORED-LIBC-FORK.md` |
**Correct pattern (path dep):**
```toml
+85
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@@ -0,0 +1,85 @@
# Vendored `libc` Fork — Redox `waitid` Surface
**Status:** TEMPORARY. Vendored for as long as it is required; delete once
upstream `libc` carries the Redox bindings.
**Location:** `local/sources/libc/`
**Base:** crates.io `libc` 0.2.189, unmodified except `src/unix/redox/mod.rs`.
**Established:** 2026-08-03.
Related: `LOCAL-FORK-SUPREMACY-POLICY.md`, `FORK-BUMP-PATCHING-POLICY.md`,
`local/AGENTS.md` § "Local fork dependency rule".
---
## Why this fork exists
relibc implements the POSIX `waitid` surface in full, but the `libc` crate's
Redox bindings never exposed it — and still do not as of 0.2.189. Any crate
that calls `waitid` therefore cannot build for `x86_64-unknown-redox`:
```
error[E0531]: cannot find unit struct, unit variant or constant
`CLD_EXITED` in crate `libc`
error[E0531]: cannot find unit struct, unit variant or constant
`P_ALL` in crate `libc`
```
That breaks `nix`, and through it `ctrlc` and rustc's bootstrap tooling — which
is what blocked `rust-native`, and with it the whole native toolchain
(`gcc-native`, `llvm-native`, `rust-native`) that `config/redbear-full.toml`
requires.
This is a **binding gap, not a missing implementation**. Every symbol added
here is already real in relibc:
| Symbol | relibc source | Evidence |
|---|---|---|
| `waitid()` | `src/header/sys_wait/mod.rs:153` | `nm libc.a``T waitid` |
| `idtype_t` | `src/header/sys_wait/mod.rs:17` | `pub type idtype_t = c_int` |
| `P_ALL` / `P_PID` / `P_PGID` | `src/header/sys_wait/mod.rs:20-24` | `0` / `1` / `2` |
| `CLD_*` (6) | `include/signal.h:457-467` | `CLD_EXITED 1``CLD_CONTINUED 6` |
Values and types are taken from **relibc**, not from Linux. Redox's `idtype_t`
is `c_int` where glibc uses an enum, and copying the Linux definitions would
have produced a silently wrong ABI.
## What is actually changed
One file: `src/unix/redox/mod.rs`. Every other target is byte-for-byte upstream
0.2.189, so host builds and all non-Redox targets are unaffected.
## How it is wired
`[patch.crates-io]` in the rust workspace, carried durably as
`local/patches/rust/02-libc-redox-fork.patch`:
```toml
libc = { path = "../../../../local/sources/libc" }
```
`+rb` build metadata is what makes this safe: it leaves the upstream semver
(`0.2.189`) intact, so `^0.2` requirements still resolve. A `-rb` suffix would
be read as a pre-release and fail to satisfy them — see `local/AGENTS.md`
§ "Version conventions".
Registered in `local/fork-upstream-map.toml` as a `snapshot` fork (its history
comes from the registry, not a git clone), with `src/unix/redox/mod.rs` on the
declarative expected-differ list in `verify-fork-versions.sh` so the content
check stays meaningful rather than being blanket-skipped.
## Retiring this fork
Upstream-reportable: the gap belongs in the `libc` crate. When upstream exposes
the Redox `waitid` surface:
1. Confirm `CLD_*`, `P_*`, `idtype_t` and `waitid` are all present in
`src/unix/redox/mod.rs` for the version being resolved.
2. Drop `02-libc-redox-fork.patch` from `recipes/dev/rust/recipe.toml`.
3. Remove the `libc` row from `local/fork-upstream-map.toml` and both
`libc)` arms from `verify-fork-versions.sh`.
4. Delete `local/sources/libc/`.
5. Rebuild `rust-native` to confirm `nix` still compiles.
Until then this fork stays. Bumping it follows
`FORK-BUMP-PATCHING-POLICY.md`: re-vendor the newer upstream and re-apply the
Redox block — never carry the old base forward.
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@@ -39,3 +39,9 @@ bootloader https://gitlab.redox-os.org/redox-os/bootloader.git 1.0.0 div
installer https://gitlab.redox-os.org/redox-os/installer.git 0.2.42 diverged # fork has TUI GUI + Red Bear config additions not in upstream 0.2.42 -- content check advisory only; full rebase is Phase 2.4+ work
userutils https://gitlab.redox-os.org/redox-os/userutils.git 0.1.0 snapshot
base https://gitlab.redox-os.org/redox-os/base.git main tracked
# Vendored from the crates.io registry (unrelated git history -> snapshot).
# Divergence is confined to src/unix/redox/mod.rs, which exposes the waitid
# surface relibc already implements and the libc crate still omits as of
# 0.2.189. TEMPORARY: drop this fork once upstream libc carries the Redox
# bindings. See local/docs/VENDORED-LIBC-FORK.md.
libc https://github.com/rust-lang/libc.git 0.2.189 snapshot
+4 -2
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@@ -190,7 +190,8 @@ for fork_dir in local/sources/*/; do
# whose local-patches/ dir is empty but the fork has legitimately
# diverged via direct commits need explicit entries here.
case "$fork_name" in
libredox) expected_differ+=("src/lib.rs") ;; # F_DUPFD_CLOEXEC + AcpiVerb at commit 6908adc
libredox) expected_differ+=("src/lib.rs") ;;
libc) expected_differ+=("src/unix/redox/mod.rs") ;; # waitid/CLD_*/P_* surface # F_DUPFD_CLOEXEC + AcpiVerb at commit 6908adc
redoxfs) expected_differ+=("src/filesystem.rs" "src/record.rs" \
"src/mount/redox/mod.rs" "src/mount/redox/scheme.rs") ;;
# filesystem.rs + record.rs: a936d00 (Red Bear) import Vec from
@@ -241,7 +242,8 @@ for fork_dir in local/sources/*/; do
# local-patches/ dir is empty (no patch files) but the fork
# itself has legitimately diverged via direct commits.
case "$fork_name" in
libredox) patch_modified_files+=("src/lib.rs") ;; # F_DUPFD_CLOEXEC + AcpiVerb
libredox) patch_modified_files+=("src/lib.rs") ;;
libc) patch_modified_files+=("src/unix/redox/mod.rs") ;; # F_DUPFD_CLOEXEC + AcpiVerb
redoxfs) patch_modified_files+=("src/filesystem.rs" "src/record.rs" \
"src/mount/redox/mod.rs" "src/mount/redox/scheme.rs") ;;
esac