QNX qcc toolchain sets relative CC/CXX/AR/LD paths → build scripts fail under Bazel sandbox

[dcalavrezo-qorix]

When building Rust crates that run C/C++ build.rs for QNX (e.g., iceoryx2-pal-posix), the build fails inside Bazel’s sandbox because the qcc toolchain exports relative tool paths (CC, CXX, AR, LD). In the sandboxed runfiles CWD, those paths don’t exist, so the build script panics with Os { code: 2, NotFound }.

[dcalavrezo-qorix]

Errors Encountered (chronological)

1. Invalid platform triple

Error: Invalid platform triple in supported platforms: aarch64-unknown-nto-qnx800

2. Cargo TOML env extractor panic

Can't inherit a CARGO_PKG_README which was missing from the workspace

3. bindgen can't find POSIX headers

fatal error: 'arpa/inet.h' file not found

4. QNX env not seen by build.rs (within cargo build script runner)

QNX_TARGET environment variable not set for QNX build

5. Patch application failures (Bazel git_repository patches)

• Wrong chunk / Only garbage found / file paths not matching (patch didn’t apply to fetched repo layout).

6. After propagating env, new bindgen failure (QNX neutrino header)

fatal error: 'sys/neutrino.h' file not found

Even with:

--sysroot=$QNX_TARGET
-I$QNX_TARGET/usr/include
-I$QNX_TARGET/usr/include/c++/v1

What I Tried

Toolchain & Platform

• Fixed platform triple usage to match aarch64-unknown-qnx8_0 expectations.
• Confirmed Bazel platform/toolchain selection with --platforms=@score_toolchains_rust//platforms:aarch64-unknown-qnx8_0.

Cargo workspace metadata

• Added to root Cargo.toml:

  [workspace.package]
  version = "0.1.0"
  readme = "README.md"
  license = "Apache-2.0 OR MIT"
  edition = "2021"

  → Resolved the CARGO_PKG_README panic.

Patching iceoryx2-pal-posix build.rs

• Authored a patch to make QNX include discovery more robust:
  • Prefer QNX_TARGET; if missing, fall back to BINDGEN_EXTRA_CLANG_ARGS (tokenized).
  • Proposed a further patch to also probe arch-specific include dirs (e.g. $QNX_TARGET/aarch64le/usr/include and /c++/v1) when target_os == "nto".
• Struggled applying the patch via Bazel git_repository:
  • Initial patch failed due to wrong paths/contexts.
  • Adjusted to use correct relative path (iceoryx2-pal/posix/build.rs) and patch_args = ["-p1", "-F3", "-l"].
  • Still hit patching issues in some attempts (content/paths mismatch in fetched repo).

Environment propagation into cargo build scripts

• Tried adding env via:
  • --action_env=QNX_TARGET=... etc.
  • crate.annotation(build_script_env={...}) with:
    • QNX_TARGET, QNX_HOST, QNX_CONFIGURATION_EXCLUSIVE, QNX_SHARED_LICENSE_FILE
    • BINDGEN_EXTRA_CLANG_ARGS with --sysroot and -I includes
    • Cargo target hints: TARGET=aarch64-unknown-nto-qnx800, CARGO_CFG_TARGET_OS=nto, CARGO_CFG_TARGET_ENV=nto80, CARGO_CFG_TARGET_ARCH=aarch64
• Verified that the env inside the cargo build script runner was initially missing.
• Added env to the rust_toolchain wrapper (PATH to QNX host bin; CC/CXX/AR/LD mapped to QNX tools; RUST_BACKTRACE=full).
• Confirmed via build script printing (cargo:warning=...) that env is finally visible to the build script (e.g. QNX_TARGET=/proc/self/cwd/.../target/qnx, BINDGEN_EXTRA_CLANG_ARGS=... etc.).

Bindgen include tuning

• Extended BINDGEN_EXTRA_CLANG_ARGS to include:
  • --sysroot=$QNX_TARGET
  • -I$QNX_TARGET/usr/include
  • -I$QNX_TARGET/usr/include/sys
  • -I$QNX_TARGET/usr/include/c++/v1
• Remaining gap: likely missing arch-specific includes (e.g. $QNX_TARGET/aarch64le/usr/include and /c++/v1) → sys/neutrino.h still not found.

Local path override for iceoryx2

• Switched from git rev to local path:

  [patch."https://github.com/qorix-group/iceoryx2.git"]
  iceoryx2 = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2" }
  iceoryx2-cal = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-cal" }
  iceoryx2-bb-container = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-container" }
  iceoryx2-bb-derive-macros = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-derive-macros" }
  iceoryx2-bb-elementary = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-elementary" }
  iceoryx2-bb-elementary-traits = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-elementary-traits" }
  iceoryx2-bb-lock-free = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-lock-free" }
  iceoryx2-bb-memory = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-memory" }
  iceoryx2-bb-posix = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-posix" }
  iceoryx2-bb-system-types = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-system-types" }
  iceoryx2-bb-testing = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-testing" }
  iceoryx2-bb-threadsafe = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-bb-threadsafe" }
  iceoryx2-pal-concurrency-sync = { path = "/home/dcalavrezo/sources/iceoryx2/iceoryx2-pal-concurrency-sync" }

  (or using local patch.crates-io if appropriate)
• Ensured Bazel crate_universe picks up the local source (consistent path mapping).

Current Status

• The cargo build script runner now has the expected QNX env and sysroot flags.
• bindgen fails with:

  fatal error: 'sys/neutrino.h' file not found
  

• This strongly suggests the QNX arch-specific include directories are not on clang’s search path.

Suspected Root Cause

• QNX SDP 8.0 places some headers (e.g., sys/neutrino.h) under architecture-specific include roots like:

  $QNX_TARGET/aarch64le/usr/include
  $QNX_TARGET/aarch64le/usr/include/c++/v1
  

  The current build.rs only adds the generic $QNX_TARGET/usr/include tree, so clang can’t find Neutrino headers.

Proposed Fixes

1. No code change (env-only):
   Add arch include dirs to BINDGEN_EXTRA_CLANG_ARGS:

   --sysroot=$QNX_TARGET
   -I$QNX_TARGET/usr/include
   -I$QNX_TARGET/usr/include/sys
   -I$QNX_TARGET/usr/include/c++/v1
   -I$QNX_TARGET/aarch64le/usr/include
   -I$QNX_TARGET/aarch64le/usr/include/c++/v1
   

   (Replace aarch64le with the actual arch dir in the SDK.)

2. Code change (robust):
   Patch build.rs to:

   • Keep existing QNX logic.
   • Detect CARGO_CFG_TARGET_ARCH → map to QNX arch dir (aarch64 → aarch64le, x86_64 → x86_64, etc.).
   • If $QNX_TARGET/<arch>/usr/include exists, append -I for both /usr/include and /usr/include/c++/v1.

Repro / Diagnostics

• Useful checks:

  echo $QNX_TARGET
  ls $QNX_TARGET/usr/include/sys/neutrino.h
  ls $QNX_TARGET/aarch64le/usr/include/sys/neutrino.h
  find $QNX_TARGET -name neutrino.h

• Build with:

  --sandbox_debug --verbose_failures --subcommands

  to see env passed into the cargo build script runner.