Os { code: 2, kind: NotFound, message: "No such file or directory" }

[ghost]

What is the name of the missing file?

This also illustrates a deeper concern likely present in most idiomatic Rust programs:

• the stacktrace won't let you easily find out the name of the missing file (all you see is built.rs:7 but no callers within that)
• the error propagation idiomacy doesn't keep track of some sort of its own stacktrace(that I'm aware of, and I don't know much) to present to me when the "No such file or directory" error is shown.

     Running `/home/xftroxgpx/build/2nonpkgs/rust.stuff/rustlearnage/target/debug/build/built_example-8e075d35037f8c84/build-script-build`
error: failed to run custom build command for `built_example v0.1.0 (file:///home/xftroxgpx/build/2nonpkgs/rust.stuff/rustlearnage/built_example)`
process didn't exit successfully: `/home/xftroxgpx/build/2nonpkgs/rust.stuff/rustlearnage/target/debug/build/built_example-8e075d35037f8c84/build-script-build` (exit code: 101)
--- stderr
thread 'main' panicked at 'Failed to acquire build-time information: Os { code: 2, kind: NotFound, message: "No such file or directory" }', libcore/result.rs:945:5
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at libstd/sys_common/backtrace.rs:59
             at libstd/panicking.rs:380
   3: std::panicking::default_hook
             at libstd/panicking.rs:396
   4: std::panicking::rust_panic_with_hook
             at libstd/panicking.rs:576
   5: std::panicking::begin_panic
             at libstd/panicking.rs:537
   6: std::panicking::begin_panic_fmt
             at libstd/panicking.rs:521
   7: rust_begin_unwind
             at libstd/panicking.rs:497
   8: core::panicking::panic_fmt
             at libcore/panicking.rs:71
   9: core::result::unwrap_failed
             at /home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/src/libcore/macros.rs:23
  10: <core::result::Result<T, E>>::expect
             at /home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/src/libcore/result.rs:809
  11: build_script_build::main
             at ./build.rs:7
  12: std::rt::lang_start::{{closure}}
             at /home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/src/libstd/rt.rs:74
  13: std::panicking::try::do_call
             at libstd/rt.rs:59
             at libstd/panicking.rs:479
  14: __rust_maybe_catch_panic
             at libpanic_unwind/lib.rs:102
  15: std::rt::lang_start_internal
             at libstd/panicking.rs:458
             at libstd/panic.rs:358
             at libstd/rt.rs:58
  16: std::rt::lang_start
             at /home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/src/libstd/rt.rs:74
  17: main
  18: __libc_start_main
  19: _start

build.rs:7 is:

extern crate built;
fn main() {
//    let opts=built::Options::default() //temporary value does not live long enough
//        .set_dependencies(true);
    let mut opts=built::Options::default();                                                                                            
    opts.set_dependencies(true);
    built::write_built_file_with_opts2(&opts).expect("Failed to acquire build-time information");  //this be line 7
}

main.rs is:

// Use of a mod or pub mod is not actually necessary.
pub mod built_info {
   // The file has been placed there by the build script.
   include!(concat!(env!("OUT_DIR"), "/built.rs"));
}

fn main() {                                                                                                                            
    println!("Hello, world! it's me {}", built_info::PKG_NAME);
    //let a=built_info.iterator();
    //src: https://github.com/lukaslueg/built
    println!("This is version {}{}, built for {} by {}.",
       built_info::PKG_VERSION,
       built_info::GIT_VERSION.map_or_else(|| "".to_owned(),
                                           |v| format!(" (git {})", v)),
       built_info::TARGET,
       built_info::RUSTC_VERSION);
    eprintln!("I was built with profile \"{}\", features \"{}\" on {} using {{}}",
       built_info::PROFILE,
       built_info::FEATURES_STR,
       built_info::BUILT_TIME_UTC
       //,built_info::DEPENDENCIES_STR //fail, not defined! https://github.com/lukaslueg/built/issues/10
       );

    println!("authors {}", built_info::PKG_AUTHORS);
}

write_built_file_with_opts2 is:

diff --git a/src/lib.rs b/src/lib.rs
index f9b8d545..59c58c40 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -808,9 +808,16 @@ pub fn write_built_file_with_opts<P: AsRef<path::Path>, Q: AsRef<path::Path>>(
 /// A shorthand for calling `write_built_file()` with `CARGO_MANIFEST_DIR` and
 /// `[OUT_DIR]/built.rs`.
 pub fn write_built_file() -> io::Result<()> {
+    write_built_file_with_opts2(&Options::default())?;
+    Ok(())
+}
+
+/// A shorthand for calling `write_built_file_with_opts()` with `CARGO_MANIFEST_DIR` ,
+/// `[OUT_DIR]/built.rs` and the provided `options`.
+pub fn write_built_file_with_opts2(options: &Options) -> io::Result<()> { //XXX: cannot use same name function, even tho they have different number of args - ie. function overloading!(and this isn't part of a struct)
     let src = env::var("CARGO_MANIFEST_DIR").unwrap();
     let dst = path::Path::new(&env::var("OUT_DIR").unwrap()).join("built.rs");
-    write_built_file_with_opts(&Options::default(), &src, &dst)?;
+    write_built_file_with_opts(options, &src, &dst)?;
     Ok(())
 }
 

Ok now to save anyone some time, I'm guessing(!) that the name of the file is:

but you see what I mean? it's not easy to figure it out really, from just the stacktrace and the generic "No such file or directory" error.
This is my biggest Rust show-stopper yet! And man, I am dissapoint! :)
(I can only hope that I'm missing something that I just can't see right now; like there's some way the error includes the stacktrace of all the places it was handed off to and that can be somehow shown; or the error can be made to show the filename)
EDIT: looks like what I want, to restore some faith in Rust, is https://docs.rs/error-chain/0.11.0/error_chain/
EDIT: failure seems to be a potentially better error-chain? https://github.com/withoutboats/failure Well, at least according to this

It is intended to replace error management based on std::error::Error with a new system based on lessons learned over the past several years, including those learned from experience with quick-error and error-chain.

[ghost]

Assuming the name of the missing file is Cargo.lock AND we're inside a cargo workspace, then the file can be found only in workspace root dir, ie.

$ time cargo metadata --format-version 1 | json_reformat | grep workspace_root
!! LD_LIBRARY_PATH=/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib:
!! Executing '/home/xftroxgpx/build/2nonpkgs/rust.stuff/cargo/cargo//target/release//cargo' with args: 'metadata --format-version 1'
    "workspace_root": "/home/xftroxgpx/build/2nonpkgs/rust.stuff/rustlearnage"

real	0m0.432s
user	0m0.397s
sys	0m0.044s

instead of in CARGO_MANIFEST_DIR which for my particular case is:

$ time cargo metadata --format-version 1 | json_reformat | grep root|grep built_example
!! LD_LIBRARY_PATH=/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/build/2nonpkgs/rust.stuff/rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:/home/xftroxgpx/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib:
!! Executing '/home/xftroxgpx/build/2nonpkgs/rust.stuff/cargo/cargo//target/release//cargo' with args: 'metadata --format-version 1'
        "root": "built_example 0.1.0 (path+file:///home/xftroxgpx/build/2nonpkgs/rust.stuff/rustlearnage/built_example)"

real	0m0.418s
user	0m0.381s
sys	0m0.049s

[lukaslueg]

I'm closing this for now, please re-open if this is still a problem

[chirag-bgh]

@lukaslueg I've the same issue

[correabuscar]

For 0.7.2, the code is here:

built/src/dependencies.rs

Line 71 in acc6475

fs::File::open(manifest_location.join("Cargo.lock"))?.read_to_string(&mut lock_buf)?;

the fix might be this:
#33 (comment)

To trigger the issue:

[build-dependencies]
built = { version="0.7.2", features = [ "dependency-tree" ] }

ie. it needs dependency-tree feature which is off by default.

output:

error: failed to run custom build command for `binprog v0.1.0 (/tmp/1/binprog)`

Caused by:
  process didn't exit successfully: `/tmp/1/target/debug/build/binprog-ea16158480722438/build-script-build` (exit status: 101)
  --- stderr
  thread 'main' panicked at /tmp/1/binprog/build.rs:43:31:
  Failed to acquire build-time information: Os { code: 2, kind: NotFound, message: "No such file or directory" }
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

why? because this is a project in a workspace, so Cargo.lock is not in current dir but in parent dir.

With the fix, it would look like this:

error: failed to run custom build command for `binprog v0.1.0 (/tmp/1/binprog)`

Caused by:
  process didn't exit successfully: `/tmp/1/target/debug/build/binprog-55a0bbd182871c65/build-script-build` (exit status: 101)
  --- stderr
  Failed to open Cargo.lock. This information is only available for top-level packages. See the documentation for `built::Options::set_dependencies`.
  thread 'main' panicked at /tmp/1/binprog/build.rs:43:31:
  Failed to acquire build-time information: Os { code: 2, kind: NotFound, message: "No such file or directory" }
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Not sure when this other code is supposed to execute, but might need same fix:

built/src/dependencies.rs

Line 141 in acc6475

fs::File::open(manifest_location.join("Cargo.lock"))?.read_to_string(&mut lock_buf)?;