Tauri android dev fails trying to build libdbus-sys on Arch Linux

[lcdss]

I'm new using Rust and Tauri and I'm building a desktop app to control a few things on my computer remotely (only LAN for now). Now I need to test it on android but I can't make the package (libdbus-sys) to compile on my system, so if anyone had this problem before or knows how to fix it, please share your wisdom 😄

[...]
Compiling libdbus-sys v0.2.5
error: failed to run custom build command for `libdbus-sys v0.2.5`

Caused by:
  process didn't exit successfully: `/mnt/shared/Code/pc-remote-control/src-tauri/target/debug/build/libdbus-sys-697d028c6596afbd/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=build.rs
  [...]

  --- stderr
  pkg_config failed: pkg-config has not been configured to support cross-compilation.

  Install a sysroot for the target platform and configure it via
  PKG_CONFIG_SYSROOT_DIR and PKG_CONFIG_PATH, or install a
  cross-compiling wrapper for pkg-config and set it via
  PKG_CONFIG environment variable.
  One possible solution is to check whether packages
  'libdbus-1-dev' and 'pkg-config' are installed:
  On Ubuntu:
  sudo apt install libdbus-1-dev pkg-config
  On Fedora:
  sudo dnf install dbus-devel pkgconf-pkg-config

  thread 'main' panicked at /home/lcss/.asdf/installs/rust/nightly/registry/src/index.crates.io-6f17d22bba15001f/libdbus-sys-0.2.5/build.rs:25:9:
  explicit panic
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...
    Error `Failed to run `cargo build`: command ["cargo", "build", "--package", "pc-remote-control", "--manifest-path", "/mnt/shared/Code/pc-remote-control/src-tauri/Cargo.toml", "--target", "aarch64-linux-android", "--lib"] exited with code 101
 ELIFECYCLE  Command failed with exit code 1.

[✔] Environment
    - OS: EndeavourOS Rolling Release X64
    ✔ webkit2gtk-4.1: 2.44.3
    ✔ rsvg2: 2.58.3
    ✔ rustc: 1.80.1 (3f5fd8dd4 2024-08-06)
    ✔ cargo: 1.80.1 (376290515 2024-07-16)
    ✔ rustup: 1.27.1 (54dd3d00f 2024-04-24)
    ✔ Rust toolchain: stable-x86_64-unknown-linux-gnu (default)
    - node: 22.5.1
    - pnpm: 9.7.1
    - npm: 10.8.2
    - bun: 1.1.20

[-] Packages
    - tauri [RUST]: 2.0.0-rc.6
    - tauri-build [RUST]: 2.0.0-rc.6
    - wry [RUST]: 0.42.0
    - tao [RUST]: 0.29.1
    - @tauri-apps/api : not installed!
    - @tauri-apps/cli [NPM]: 2.0.0-rc.6

[-] App
    - build-type: bundle
    - CSP: unset
    - frontendDist: ../dist
    - devUrl: http://localhost:1420/
    - framework: React
    - bundler: Vite

Environment variables defined:

$env.JAVA_HOME = "/opt/android-studio/jbr"
$env.PKG_CONFIG = "/usr/bin/pkg-config"
$env.PKG_CONFIG_PATH = "/usr/lib/pkgconfig"
$env.ANDROID_HOME = ($env.HOME | path join Android sdk)
$env.NDK_HOME = ($env.ANDROID_HOME | path join ndk 27.0.12077973)
$env.CARGO_HOME = ($env.ASDF_DIR | path join installs rust nightly)

/home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android35-clang --version:

Android (12027248, +pgo, +bolt, +lto, +mlgo, based on r522817) clang version 18.0.1 (https://android.googlesource.com/toolchain/llvm-project d8003a456d14a3deb8054cdaa529ffbf02d9b262)
Target: aarch64-unknown-linux-android35
Thread model: posix
InstalledDir: /home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin

After setting the env PKG_CONFIG_PATH to /usr/lib/pkgconfig, where dbus-1.pc file and others are the error changed:

Error Library artifact not found at /mnt/shared/Code/lcss/pc-remote-control/src-tauri/target/aarch64-linux-android/debug/libpc_remote_control.so. Make sure your Cargo.toml file has a [lib] block with `crate-type = ["staticlib", "cdylib", "rlib"]`

I copied that to Cargo.toml file and now the new error is:

error: linking with `/home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang` failed: exit status: 1
  |
  = note: LC_ALL="C" PATH="/home/lcss/.asdf/installs/rust/nightly/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/bin:/home/lcss/.asdf/installs/rust/nightly/too
[....]
all" "-nodefaultlibs" "-landroid" "-llog" "-lOpenSLES"
  = note: ld.lld: error: --fix-cortex-a53-843419 is only supported on AArch64 targets
          clang: error: linker command failed with exit code 1 (use -v to see invocation)

I tried different ndk versions and setting the linker and rustflags in the src-tauri/.cargo/config.toml file (which is automatically created when running android dev or android build commands for the first time)

[build]
target = "x86_64-unknown-linux-gnu"

[target.aarch64-linux-android]
linker = "/home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android35-clang"
rustflags = []

but it keeps being ignored as it use aarch64-linux-android24-clang and not the aarch64-linux-android35-clang:

error: linking with `/home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang` failed: exit status: 1
[...]
note: ld.lld: error: --fix-cortex-a53-843419 is only supported on AArch64 targets
          clang: error: linker command failed with exit code 1 (use -v to see invocation)

And if I try to run the command
cargo build --package pc-remote-control --manifest-path ./Cargo.toml --target aarch64-linux-android --lib
it fails too:

[...]
Compiling zstd-sys v2.0.13+zstd.1.5.6
The following warnings were emitted during compilation:

warning: zstd-sys@2.0.13+zstd.1.5.6: Compiler family detection failed due to error:
ToolNotFound: Failed to find tool. Is `aarch64-linux-android-clang` installed?

The same happens after setting the envs:

export CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="/home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-clang"
export CC_aarch64_linux_android="/home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-clang"
export CFLAGS_aarch64_linux_android="-v"

and

ln -s /home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android35-clang /home/lcss/Android/sdk/ndk/27.0.12077973/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-clang

It seems nothing really matters at this point.

[FabianLars]

Is this still an issue? dbus is not supposed to be compiled for android afaik so this sounds like some dekstop-only crates are incorrectly enabled for mobile targets. Did you check whether a plain create-tauri-app project throws the same errors?

[lcdss]

I've just found a solution to my problem. The problem was the mpris crate. So moving all dependencies used only by the desktop to its own dependencies block, solved the problem I was facing for two weeks. I was almost giving up and moving the mobile version to React Native.

[dependencies]
serde_json = "1"
tauri = { version = "2.0.0-rc", features = ["tray-icon"] }

[target.'cfg(target_os = "linux")'.dependencies]
actix-cors = "0"
actix-web = "4"
lazy-regex = "3.3.0"
mpris = "2"
serde = "1"
tauri-plugin-shell = "2.0.0-rc"
tokio = "1"

After all the uncountable hours I spent trying to find a solution , I just want to highlight that the error messages I got was completely unhelpful. After the changes I made on the system side, the error changed to ... --fix-cortex-a53-843419 ... and there was nothing pointing to dbus anymore.