Cargo prints "Compiling <crate>" when build script runs, and gives no indication when the final crate artefact is being built

[huonw]

[package]

name = "a"
version = "0.0.1"
authors = []
build = "build.rs"

[dependencies.compile_msg]
git = "https://github.com/huonw/compile_msg"

// build.rs
fn main() {}

// src/main.rs
fn main() { println!("hi") }

$ cargo clean && cargo build
   Compiling a v0.0.1 (file:///home/huon/projects/test-rust/tmp/a)
   Compiling compile_msg v0.1.0 (https://github.com/huonw/compile_msg#569c6f18)
$ ./target/a # it worked!
hi

Without the build = ... line the output of cargo build is

   Compiling compile_msg v0.1.0 (https://github.com/huonw/compile_msg#569c6f18)
   Compiling a v0.0.1 (file:///home/huon/projects/test-rust/tmp/a)

I was expecting something like

   Compiling build command a v0.0.1 (file:///home/huon/projects/test-rust/tmp/a)
   Compiling compile_msg v0.1.0 (https://github.com/huonw/compile_msg#569c6f18)
   Compiling a v0.0.1 (file:///home/huon/projects/test-rust/tmp/a)

(Possibly renaming the first line to Executing build command ... or even having a separate line for when it is executed.)

[alexcrichton]

There's definitely a balance here in not wanting to inundate users with overwhelming amounts of log output while also providing a meaningful set of output. The current rationale is basically to print precisely one message per package, and that message is printed when the first nontrivial step is run.

cc @wycats, you've had opinions on this before.

[reem]

I also found this behavior unintuitive and expected something like Compiling build command

[mrhota]

Unintuitive. The documentation doesn't seem to mention the fact that any output of build commands is printed into a file in target/debug/build//output and cargo gives zero indication that the build script has been 1) compiled or 2) executed.

[weihanglo]

Triage: Not sure if this 8-year-old issue is still relevant. Today you can use cargo build --verbose to look the exact commands Cargo runs. It shows first compiling the build script and second running the build-script-build executable. Cargo is already verbose hence we don't want more messages coming out.

It is also unclear to me why people want to know if a build script is compiling. If that is in regard to inspecting build failures, #11636 improved it a bit in 1.70.0.

In terms of progress message enhancement, we are looking forward to an overhaul of the entire progress ouptut in Cargo. #8889 is the main tracking issue for that. Going to close this. If you have opinions, please comment here or in #8889.