Possible issue with `luajit` & `pkgconf` or not detecting `pkg-config`?

[joshcangit]

Maybe this crate can require either pkgconf or pkg-config?

I'm using Ubuntu 24.04 with only pkgconf and most if not all packages already can work with either pkgconf or pkg-config.

I've been without pkg-config since 22.04 and somehow this crate cannot detect my luajit system package.
I've even just reinstall pkg-config for this.
But I still get the error anyway.

error: failed to run custom build command for `mlua-sys v0.6.7`

Caused by:
  process didn't exit successfully: `/tmp/cargo-installXwSsZj/release/build/mlua-sys-5c520965625da6e5/build-script-main` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=build
  cargo:rerun-if-env-changed=LUA_LIB
  cargo:rerun-if-env-changed=LUA_LIB_NAME
  cargo:rerun-if-env-changed=LUA_LINK
  cargo:rerun-if-env-changed=LUAJIT_NO_PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG_x86_64-unknown-linux-gnu
  cargo:rerun-if-env-changed=PKG_CONFIG_x86_64_unknown_linux_gnu
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG
  cargo:rerun-if-env-changed=LUAJIT_STATIC
  cargo:rerun-if-env-changed=LUAJIT_DYNAMIC
  cargo:rerun-if-env-changed=PKG_CONFIG_ALL_STATIC
  cargo:rerun-if-env-changed=PKG_CONFIG_ALL_DYNAMIC
  cargo:rerun-if-env-changed=PKG_CONFIG_PATH_x86_64-unknown-linux-gnu
  cargo:rerun-if-env-changed=PKG_CONFIG_PATH_x86_64_unknown_linux_gnu
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG_PATH
  cargo:rerun-if-env-changed=PKG_CONFIG_PATH
  cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_x86_64-unknown-linux-gnu
  cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR_x86_64_unknown_linux_gnu
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG_LIBDIR
  cargo:rerun-if-env-changed=PKG_CONFIG_LIBDIR
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_x86_64-unknown-linux-gnu
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_x86_64_unknown_linux_gnu
  cargo:rerun-if-env-changed=HOST_PKG_CONFIG_SYSROOT_DIR
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR

  --- stderr

  thread 'main' panicked at /home/joshua/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/mlua-sys-0.6.7/build/find_normal.rs:67:30:
  cannot find LuaJIT using `pkg-config`: 
  pkg-config exited with status code 1
  > PKG_CONFIG_ALLOW_SYSTEM_LIBS=1 PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1 pkg-config --libs --cflags luajit 'luajit >= 2.0.4' 'luajit < 2.2'

  The system library `luajit` required by crate `mlua-sys` was not found.
  The file `luajit.pc` needs to be installed and the PKG_CONFIG_PATH environment variable must contain its parent directory.
  The PKG_CONFIG_PATH environment variable is not set.

  HINT: if you have installed the library, try setting PKG_CONFIG_PATH to the directory containing `luajit.pc`.

  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...
error: failed to compile `lux-cli v0.3.0`, intermediate artifacts can be found at `/tmp/cargo-installXwSsZj`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.
ERROR Cargo errored! ExitStatus(unix_wait_status(25856))
ERROR Fatal error:
  × For crate lux-cli: subprocess /opt/rustup/toolchains/stable-x86_64-
  │ unknown-linux-gnu/bin/cargo install lux-cli --version 0.3.0 errored with
  │ exit status: 101
  ╰─▶ subprocess /opt/rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/
      cargo install lux-cli --version 0.3.0 errored with exit status: 101

[khvzak]

mlua uses on pkg-config-rs for finding packages in the system. It should support pkgconf (see rust-lang/pkg-config-rs#145) out of the box.

Testing on the clean system:

> docker run -it --rm ubuntu:24.04
$ apt update
$ apt install -y curl build-essential
$ apt install -y pkgconf libssl-dev libgpgme-dev libluajit-5.1-dev
# Install Rust
$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# Activate Rust
$ . "$HOME/.cargo/env"
# Install lux-cli
$ cargo install lux-cli
$ lx -V
lux-cli 0.3.0
# pkg-config is NOT installed
$ dpkg -l | grep pkg-config
$

So I can confirm that pkg-config is not required for mlua-sys

[joshcangit]

Yeah, I was missing the libluajit-5.1-dev package.