could not find X11

[cstkingkey]

Checklist

• I've looked through the issues and pull requests for similar reports

Describe your issue

build fltk-rs (https://github.com/fltk-rs/fltk-rs) with https://github.com/fltk-rs/fltk-rs
run into
-- Could NOT find X11 (missing: X11_X11_INCLUDE_PATH X11_X11_LIB)
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE
-- Pango requires Xft but Xft library or headers could not be found.
-- Please install Xft development files and try again or disable OPTION_USE_PANGO.
-- Configuring incomplete, errors occurred!

What target(s) are you cross-compiling for?

No response

Which operating system is the host (e.g computer cross is on) running?

• macOS
• Windows
• Linux / BSD
• other OS (specify in description)

What architecture is the host?

• x86_64 / AMD64
• arm32
• arm64 (including Mac M1)

What container engine is cross using?

• docker
• podman
• other container engine (specify in description)

cross version

cross 0.2.4

Example

No response

Additional information / notes

No response

[cstkingkey]

following packages are installed in the custom image
libx11-dev:arm64 libxext-dev:arm64 libxft-dev:arm64 libxinerama-dev:arm64 libxcursor-dev:arm64 libxrender-dev:arm64 libxfixes-dev:arm64 libwayland-dev:arm64 wayland-protocols libdbus-1-dev:arm64 libxkbcommon-dev:arm64 libpango1.0-dev:arm64 libgl1-mesa-dev:arm64 libglu1-mesa-dev:arm64

[cstkingkey]

Image is built with cross aa59bf2 using cargo build-docker-image

[Emilgardis]

How exactly are you installing these dependencies in the custom image built with cargo build-docker-image?

[cstkingkey]

How exactly are you installing these dependencies in the custom image built with cargo build-docker-image?

get the base image with cargo build-docker-image, then build the custom image with following Dockerfile

FROM ghcr.io/cross-rs/aarch64-unknown-linux-gnu:local

ENV DEBIAN_FRONTEND=noninteractive

RUN dpkg --add-architecture arm64 &&
apt-get update &&
apt-get install --assume-yes --no-install-recommends
libx11-dev:arm64 libxext-dev:arm64 libxft-dev:arm64
libxinerama-dev:arm64 libxcursor-dev:arm64
libxrender-dev:arm64 libxfixes-dev:arm64
libwayland-dev:arm64 wayland-protocols libdbus-1-dev:arm64 libxkbcommon-dev:arm64
libpango1.0-dev:arm64 libgl1-mesa-dev:arm64 libglu1-mesa-dev:arm64

[Emilgardis]

Alright, this might be an issue with how fltk-sys (or really the cmake build) discovers packages.

Any reason you're using cargo build-docker-image and not any of the options listed in the wiki?

Does setting X11_X11_INCLUDE_PATH and X11_X11_LIB solve the issue?

It should be X11_X11_LIB=/usr/lib/aarch64-linux-gnu/ and X11_X11_INCLUDE_PATH=/usr/include/X11/

[cstkingkey]

Alright, this might be an issue with how fltk-sys (or really the cmake build) discovers packages.

Any reason you're using cargo build-docker-image and not any of the options listed in the wiki?

Does setting X11_X11_INCLUDE_PATH and X11_X11_LIB solve the issue?

It should be X11_X11_LIB=/usr/lib/aarch64-linux-gnu/ and X11_X11_INCLUDE_PATH=/usr/include/X11/

No, same error log.
The reason is not very straightforward.
I try to build macos image. Then I try to update the linux arm64 image as the one I'm using is pretty old which is based on rustembedded/cross:aarch64-unknown-linux-gnu.

[cstkingkey]

comment out following code in toolchain.cmake will make it work
if(DEFINED ENV{CROSS_SYSROOT})
set(CMAKE_FIND_ROOT_PATH "$ENV{CROSS_SYSROOT}" "${CMAKE_PREFIX_PATH}")
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
endif()

[MoAlyousef]

The set(CMAKE_FIND_ROOT_PATH "$ENV{CROSS_SYSROOT}" "${CMAKE_PREFIX_PATH}") seems wrong.

CMAKE_PREFIX_PATH is empty by default, and is only filled if a path is given using set(CMAKE_PREFIX_PATH some/path) or using the command-line: cmake -B bin -DCMAKE_PREFIX_PATH=some/path.
Also for example on aarch64-linux-gnu, CROSS_SYSROOT is set to /usr/aarch64-linux-gnu, this makes searching for libs and headers happen in $CROSS_SYSROOT/include and $CROSS_SYSROOT/lib, while in reality, they are installed in /usr/include/aarch64-linux-gnu/ and /usr/lib/aarch64-linux-gnu.

I can confirm fltk-rs used to build using cross-rs, but currently it doesn't with:

FROM ghcr.io/cross-rs/aarch64-unknown-linux-gnu:edge

ENV DEBIAN_FRONTEND=noninteractive

RUN dpkg --add-architecture arm64 && \
    apt-get update && \
    apt-get install --assume-yes --no-install-recommends \
    libx11-dev:arm64 libxext-dev:arm64 libxft-dev:arm64 \
    libxinerama-dev:arm64 libxcursor-dev:arm64 \
    libxrender-dev:arm64  libxfixes-dev:arm64  libgl1-mesa-dev:arm64 \
    libglu1-mesa-dev:arm64 libasound2-dev:arm64 libpango1.0-dev:arm64

and Cross.toml:

[target.aarch64-unknown-linux-gnu]
dockerfile = "./arm64-dockerfile"

cross build --target aarch64-unknown-linux-gnu

I think cross-rs shouldn't be passing a CMAKE_TOOLCHAIN_FILE to every build since that breaks any repo which uses its own toolchain file or using a toolchain file provided by a vendor, like the android cmake toolchain file for example.

A minimal repro using the cmake crate (only requiring X11, no fltk):

|
|__csrc
|        |_lib.c
|        |_CMakeLists.txt
|_src
|     |_main.rs
|
|_Cargo.toml
|
|_Cross.toml
|
|_build.rs
|
|_arm64-dockerfile

// build.rs
fn main() {
    let out_dir = std::path::PathBuf::from(std::env::var("OUT_DIR").unwrap());
    let _dst = cmake::Config::new("csrc").build();
    println!(
        "cargo:rustc-link-search=native={}",
        out_dir.join("lib").display()
    );
    println!("cargo:rustc-link-lib=static=cx11");
}

# Cargo.toml
[package]
name = "cros2"
version = "0.1.0"
edition = "2021"

[build-dependencies]
cmake = "*"

# Cross.toml
[target.aarch64-unknown-linux-gnu]
dockerfile = "./arm64-dockerfile"

# arm64-dockerfile
FROM ghcr.io/cross-rs/aarch64-unknown-linux-gnu:edge

ENV DEBIAN_FRONTEND=noninteractive

RUN dpkg --add-architecture arm64 && \
    apt-get update && \
    apt-get install --assume-yes --no-install-recommends \
    libx11-dev:arm64

// csrc/lib.c
int cmain() {
    return 0;
}

# csrc/CMakeLists.txt
cmake_minimum_required(VERSION 3.14)
project(cx11)

find_package(X11 REQUIRED) # this will fail
add_library(cx11 lib.c)

# cmake-rs requires an install target
install(TARGETS cx11
    EXPORT cx11Config
    ARCHIVE DESTINATION ${CMAKE_INSTALL_PREFIX}/lib
    LIBRARY DESTINATION ${CMAKE_INSTALL_PREFIX}/lib
    )

// src/main.rs
fn main() {
    println!("Hello, world!");
}

build with cross build --target=aarch64-unknown-linux-gnu will also fail with a similar error.