cbindgen panicks when parse-expand is run inside of buildscript due to inability to acquire semaphore #347
Description
I have successfully run cbingen on the command-line using the following cbindgen.toml:
include_guard = "SE4_CORE_BINDINGS_H_"
include_version = true
braces = "SameLine"
line_length = 100
tab_width = 4
[export]
prefix = "SE4"
[parse]
parse_deps = false
[parse.expand]
crates = ["se4_capi"]I decided to add it as a build script:
extern crate cbindgen;
use std::env;
fn main() {
let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
cbindgen::generate(crate_dir)
.expect("Unable to generate bindings")
.write_to_file("include/bindings.h");
}Upon execution, of cargo build cbindgen instantly crashes. It seems like cbindgen tries to acquire a lock on the build directory that was previously acquired by cargo, and thus crashes after outputing the following:
Blocking waiting for file lock on build directory
Compiling se4_capi v0.1.0
error: failed to run custom build command for `se4_capi v0.1.0`
Caused by:
process didn't exit successfully: `build-script-build` (exit code: 101)
--- stderr
thread 'main' panicked at 'Unable to generate bindings: CargoExpand("se4_capi", Compile(" Blocking waiting for file lock on build directory\nerror: Too many posts were made to a semaphore. (os error 298)\n"))', src\libcore\result.rs:999:5
stack backtrace:
0: std::sys::windows::backtrace::set_frames
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\sys\windows\backtrace\mod.rs:95
1: std::sys::windows::backtrace::unwind_backtrace
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\sys\windows\backtrace\mod.rs:82
2: std::sys_common::backtrace::_print
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\sys_common\backtrace.rs:71
3: std::sys_common::backtrace::print
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\sys_common\backtrace.rs:59
4: std::panicking::default_hook::{{closure}}
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:197
5: std::panicking::default_hook
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:211
6: std::panicking::rust_panic_with_hook
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:474
7: std::panicking::continue_panic_fmt
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:381
8: std::panicking::rust_begin_panic
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:308
9: core::panicking::panic_fmt
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libcore\panicking.rs:85
10: core::result::unwrap_failed<cbindgen::bindgen::error::Error>
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\src\libcore\macros.rs:18
11: core::result::Result<cbindgen::bindgen::bindings::Bindings, cbindgen::bindgen::error::Error>::expect<cbindgen::bindgen::bindings::Bindings,cbindgen::bindgen::error::Error>
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\src\libcore\result.rs:827
12: build_script_build::main
at .\build.rs:9
13: std::rt::lang_start::{{closure}}<()>
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\src\libstd\rt.rs:64
14: std::rt::lang_start_internal::{{closure}}
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\rt.rs:49
15: std::panicking::try::do_call<closure,i32>
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:293
16: panic_unwind::__rust_maybe_catch_panic
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libpanic_unwind\lib.rs:85
17: std::panicking::try
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panicking.rs:272
18: std::panic::catch_unwind
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\panic.rs:388
19: std::rt::lang_start_internal
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\/src\libstd\rt.rs:48
20: std::rt::lang_start<()>
at /rustc/37ff5d388f8c004ca248adb635f1cc84d347eda0\src\libstd\rt.rs:64
21: main
22: invoke_main
at d:\agent\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:78
23: __scrt_common_main_seh
at d:\agent\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
24: BaseThreadInitThunk
25: RtlUserThreadStart
I am aware of PR #72, and as such attempted to set CARGO_EXPAND_TARGET_DIR, but the only change was that it took a little longer for the panick to occur.
env::set_var("CARGO_EXPAND_TARGET_DIR", crate_dir.clone());I also read PR #153 which seems to have a similar problem, except that it doesn't result in a panick.
To use cbindgen I swapped to nightly, as it was required for expanding macros. I am currently at:
nightly-x86_64-pc-windows-msvc (default)
rustc 1.36.0-nightly (37ff5d388 2019-05-22)