Fail to build for aarch64-unknown-linux-gnu

[Dituon]

I get some error when trying to cross compile for aarch64-unknown-linux-gnu

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

• Host WSL Ubuntu (x86_64)
• Rustc 1.76.0
• skia-safe { version = "0.72.0", features = ["gl", "gpu", "textlayout"] }
• cross-rs 0.2.5 Docker

See #756 , I tried building for aarch64-unknown-linux-gnu with 0.72.0 binaries,
The following error occurred during the final linking step.

(Some parts have been omitted for easier reading)

error: linking with `aarch64-linux-gnu-gcc` failed: exit status: 1
  |
  = note: LC_ALL="C" PATH="/rust/lib/rustlib/x86_64-unknown-linux-gnu/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/rust/bin" VSLANG="1033" "aarch64-linux-gnu-gcc" ...
  
    = note: /usr/aarch64-linux-gnu/bin/ld: cannot find -lfontconfig
          /usr/aarch64-linux-gnu/bin/ld: cannot find -lfreetype
          collect2: error: ld returned 1 exit status

I think the linker cannot find libfontconfig and libfreetype. Are these two libraries not included in the pre-built binary?

Should I cross compile these two libraries and set LD_LIBRARY_PATH ?

[tronical]

Yes, these two libraries need to be supplied in system library search paths.

[Dituon]

Thank you, I tried to install dependent libraries libfontconfig1-dev and libfreetype6-dev from apt

(cross-rs config)

[package.metadata.cross.build]
pre-build = [
    "dpkg --add-architecture $CROSS_DEB_ARCH",
    "apt-get update && apt-get --assume-yes install libfontconfig1-dev:$CROSS_DEB_ARCH libfreetype6-dev:$CROSS_DEB_ARCH",
    "cp -r /usr/lib/aarch64-linux-gnu/* /usr/aarch64-linux-gnu/lib/",
]

(build.rs)

fn main() {
    println!("cargo:rustc-link-lib=fontconfig");
    println!("cargo:rustc-link-lib=freetype");
}

log

error: linking with `aarch64-linux-gnu-gcc` failed: exit status: 1
  |
  = note: LC_ALL="C" ...

  = note: /target/aarch64-unknown-linux-gnu/release/deps/libskia_bindings-8b432cbf1829e2d8.rlib(typeface_freetype.SkFontHost_FreeType.o): In function `SkTypeface_FreeType::FaceRec::ref_ft_library()':
          SkFontHost_FreeType.cpp:(.text._ZN19SkTypeface_FreeType7FaceRec14ref_ft_libraryEv[_ZN19SkTypeface_FreeType7FaceRec14ref_ft_libraryEv]+0x64): undefined reference to `FT_Set_Default_Properties'
          /target/aarch64-unknown-linux-gnu/release/deps/libskia_bindings-8b432cbf1829e2d8.rlib(typeface_freetype.SkFontHost_FreeType.o): In function `GetVariationDesignPosition(AutoFTAccess&, SkFontArguments::VariationPosition::Coordinate*, int)':
          SkFontHost_FreeType.cpp:(.text._ZL26GetVariationDesignPositionR12AutoFTAccessPN15SkFontArguments17VariationPosition10CoordinateEi+0xd0): undefined reference to `FT_Get_Var_Design_Coordinates'
          /target/aarch64-unknown-linux-gnu/release/deps/libskia_bindings-8b432cbf1829e2d8.rlib(typeface_freetype.SkFontHost_FreeType.o): In function `SkTypeface_FreeType::onGetVariationDesignParameters(SkFontParameters::Variation::Axis*, int) const':
          SkFontHost_FreeType.cpp:(.text._ZNK19SkTypeface_FreeType30onGetVariationDesignParametersEPN16SkFontParameters9Variation4AxisEi+0x174): undefined reference to `FT_Get_Var_Axis_Flags'
          /target/aarch64-unknown-linux-gnu/release/deps/libskia_bindings-8b432cbf1829e2d8.rlib(typeface_freetype.SkFontHost_FreeType.o): In function `SkTypeface_FreeType::MakeFromStream(std::unique_ptr<SkStreamAsset, std::default_delete<SkStreamAsset> >, SkFontArguments const&)':
          SkFontHost_FreeType.cpp:(.text._ZN19SkTypeface_FreeType14MakeFromStreamESt10unique_ptrI13SkStreamAssetSt14default_deleteIS1_EERK15SkFontArguments+0x4bc): undefined reference to `FT_Set_Default_Properties'
          /target/aarch64-unknown-linux-gnu/release/deps/libskia_bindings-8b432cbf1829e2d8.rlib(typeface_freetype.SkFontHost_FreeType.o): In function `SkFontScanner_FreeType::scanFont(SkStreamAsset*, int, SkString*, SkFontStyle*, bool*, skia_private::STArray<4, SkFontScanner::AxisDefinition, true>*) const':
          SkFontHost_FreeType.cpp:(.text._ZNK22SkFontScanner_FreeType8scanFontEP13SkStreamAssetiP8SkStringP11SkFontStylePbPN12skia_private7STArrayILi4EN13SkFontScanner14AxisDefinitionELb1EEE+0x354): undefined reference to `FT_Get_Var_Design_Coordinates'
          collect2: error: ld returned 1 exit status

  = note: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
  = note: use the `-l` flag to specify native libraries to link
  = note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-link-libkindname)

Is the version of FreeType that skia depends on inconsistent with the version I installed? Which version should I install?

[pragmatrix]

Looks like the linker errors are the same as in issue #570, so FreeType version 2.7+ should fix the linker errors.

[Dituon]

I found the real cause of the problem

1. skia-safe depends on FreeType 2.7+
2. corss-rs 0.2.5 docker default host is Ubuntu 16.04
3. libfreetype6-dev binary package in Ubuntu 16.04 latest version is 2.6.1-0.1ubuntu2.5