lalrpop_mod! looks under build subdirectory instead of crate root

[littlebenlittle]

Running cargo build results in couldn't read target/debug/build/xmd-lalrpop-<id>/out/src/calculator1.lalrpop: no such file or directory.

I can get the build script to finish if I use lalrpop_mod!(pub calculator1, "/../../../../../src/calculator1.lalrpop") but that really doesn't look like the intended way to use the macro.

Using cargo -V cargo 1.60.0 (d1fd9fe 2022-03-01)

Project layout based on calculator example example:

.
├── build.rs
├── Cargo.lock
├── Cargo.toml
└── src
   ├── lib.rs
   └── calculator1.lalrpop

src/lib.rs:

#[macro_use] extern crate lalrpop_util;

lalrpop_mod!(pub calculator1, "/src/calculator1.lalrpop");

[an-inconspicuous-semicolon]

I found the reason for this. It is because in the macro lalrpop_mod! it looks for the file in env!("OUT_DIR")/argument-given-to-macro

The issue comes with the fact that cargo sets OUT_DIR on build. so when OUT_DIR=foobar cargo build is run, OUT_DIR gets set to the binary output dir, rather than foobar

the fix for this is to change the enviroment variable used inside lalrpop_mod! to something like LALRPOP_OUT_DIR

[an-inconspicuous-semicolon]

Also note that this is expected behavior as of v0.16.0
documentation