Error compiling ethercat-sys

[17steen]

using latest stable revision of the recommended ethercat repo, all works when using the c library, getting this error while compiling:

   Compiling ethercat-sys v0.2.0
error: failed to run custom build command for `ethercat-sys v0.2.0`

Caused by:
  process didn't exit successfully: `/home/student/Sources/rust/ethercat-connection-rs/target/debug/build/ethercat-sys-3ae150160a12e9a6/build-script-build` (exit status: 101)
  --- stderr
  thread 'main' panicked at '"ec_ioctl_slave_t_struct_(unnamed_at_/home/student/Downloads/ethercat/master/ioctl_h_228_5)" is not a valid Ident', /home/student/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-1.0.51/src/fallback.rs:752:9
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

using Ubuntu 22.04.1 LTS kernel: 5.19.0-32-generic

[17steen]

these are my configure flags: ./configure --enable-generic --disable-8139too --disable-e100 --disable-e1000 --disable-e1000e --disable-igb --disable-r8169 --disable-ccat --sysconfdir=/etc

[birkenfeld]

Can you share more details about your checkout of the master repo? You should switch to the stable-1.5 branch.

[birkenfeld]

I just realized this is not documented (except on IgH's site) and pushed an addition to README.

[17steen]

Sorry forgot to mention that, but I checked the stable branch out aswell

* stable-1.5

[birkenfeld]

Hm. Can you set the RUST_BACKTRACE=1 env var and post the traceback?

[birkenfeld]

I cannot reproduce with a fresh Ubuntu 22.04. Below is the Dockerfile I used...

FROM ubuntu:22.04

RUN apt-get update \
 && apt-get install -y autoconf libtool pkg-config make systemd git cargo linux-headers-generic libclang-dev

RUN git clone https://gitlab.com/etherlab.org/ethercat
RUN cd ethercat && git checkout stable-1.5 && ./bootstrap \
 && ./configure --enable-generic --disable-8139too --disable-e100 --disable-e1000 --disable-e1000e --disable-igb --disable-r8169 --disable-ccat --sysconfdir=/etc --with-linux-dir=/usr/src/linux-headers-*-generic

RUN git clone https://github.com/ethercat-rs/ethercat ethercat-rs
RUN cd ethercat-rs && ETHERCAT_PATH=/ethercat cargo build

Edit: now also checked with your configure flags.

[17steen]

maybe i should start with a clean repo, i had configured with other flags before

EDIT: still got the same error with that identifier

[17steen]

RUST_BACKTRACE=1 cargo build
   Compiling ethercat-sys v0.2.0
error: failed to run custom build command for `ethercat-sys v0.2.0`
note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.

Caused by:
  process didn't exit successfully: `/home/student/Sources/rust/ethercat-connection-rs/target/debug/build/ethercat-sys-3ae150160a12e9a6/build-script-build` (exit status: 101)
  --- stderr
  thread 'main' panicked at '"ec_ioctl_slave_t_struct_(unnamed_at_/home/student/Downloads/ethercat/master/ioctl_h_228_5)" is not a valid Ident', /home/student/.cargo/registry/src/github.com-1ecc6299db9ec823/proc-macro2-1.0.51/src/fallback.rs:752:9
  stack backtrace:
     0: rust_begin_unwind
               at /rustc/5b8f284536d00ba649ca968584bedab4820d8527/library/std/src/panicking.rs:575:5
     1: core::panicking::panic_fmt
               at /rustc/5b8f284536d00ba649ca968584bedab4820d8527/library/core/src/panicking.rs:64:14
     2: proc_macro2::fallback::validate_ident
     3: proc_macro2::fallback::Ident::_new
     4: proc_macro2::fallback::Ident::new
     5: proc_macro2::imp::Ident::new
     6: proc_macro2::Ident::new
     7: bindgen::ir::context::BindgenContext::rust_ident_raw
     8: bindgen::ir::context::BindgenContext::rust_ident
     9: <bindgen::ir::comp::CompInfo as bindgen::codegen::CodeGenerator>::codegen
    10: <bindgen::ir::ty::Type as bindgen::codegen::CodeGenerator>::codegen
    11: <bindgen::ir::item::Item as bindgen::codegen::CodeGenerator>::codegen
    12: <bindgen::ir::comp::CompInfo as bindgen::codegen::CodeGenerator>::codegen
    13: <bindgen::ir::ty::Type as bindgen::codegen::CodeGenerator>::codegen
    14: <bindgen::ir::item::Item as bindgen::codegen::CodeGenerator>::codegen
    15: <bindgen::ir::module::Module as bindgen::codegen::CodeGenerator>::codegen::{{closure}}
    16: <bindgen::ir::module::Module as bindgen::codegen::CodeGenerator>::codegen
    17: <bindgen::ir::item::Item as bindgen::codegen::CodeGenerator>::codegen
    18: bindgen::codegen::codegen::{{closure}}
    19: bindgen::ir::context::BindgenContext::gen
    20: bindgen::codegen::codegen
    21: bindgen::Bindings::generate
    22: bindgen::Builder::generate
    23: build_script_build::main
    24: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[17steen]

[package]
name = "ethercat-connection-rs"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
ethercat = "0.2.3"

this is my Cargo.toml

EDIT: i noticed the package is 3 months old on crates.io, this might be why

EDIT: changed to

[dependencies]
ethercat = { git = "https://github.com/ethercat-rs/ethercat" }

still get the same error

[birkenfeld]

bindgen seems to get stuck at the anonymous sub-struct in master/ioctl.h line 228. I can only imagine an incompatibility with clang (bindgen uses libclang to parse the C code). Which clang/libclang do you have installed? Can you try with the latest one, like is installed in my Docker example?

[17steen]

I am using clang-17 from LLVM's ppa's this might be it, I do not exactly know how I can instruct the build process to use the ones provided by the ubuntu repositories instead

EDIT: ppa i use , probably pretty unstable

clang --version
Ubuntu clang version 17.0.0 (++20230217042301+7c9df7743521-1~exp1~20230217042417.752)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

[17steen]

maybe i can LD_PRELOAD an older version of libclang

[17steen]

managed to build it using a fresh container as well. Once the sys package is built i can go forth outside the container, I assume, so this resolves the issue.

The unstable version of clang on my system must be the cause of the problem. Thanks for helping me find that out.

[birkenfeld]

Thanks for confirming! We also have the pregenerated-bindings feature which removes the need for the C checkout completely, however it is tied to a specific (and now outdated) revision.

Since IgH don't do release versions anymore, it's kind of hard to decide when to update them :(