[OSX] build fails

[altafan]

I'm trying to build the python wrapper for gdk on my mac (BigSur) with these steps:

$ mkdir gdk-python
$ python3 -m venv venv
$ source venv/bin/activate
$ pip install -r ./tools/requirements.txt
$ ./tools/build.sh --install $PWD/gdk-python --clang --python-version 3.9

but i get following error on the very last command (./tools/build.sh ...):

The Meson build system
Version: 0.58.0
Source dir: <datadir>/gdk
Build dir: <datadir>/gdk/build-clang
Build type: native build
Project name: gdk
Project version: 0.0.54

meson.build:1:0: ERROR: Compiler clang can not compile programs.

A full log can be found at <datadir>/gdk/build-clang/meson-logs/meson-log.txt

And this is the content of the meson-log.txt log file:

Build started at 2022-06-27T16:48:48.830448
Main binary: /usr/local/opt/python@3.9/bin/python3.9
Build Options: -Dpython-version=3.8 -Dbuildtype=release -Ddefault_library=shared -Dwerror=True
Python system: Darwin
The Meson build system
Version: 0.62.2
Source dir: <datadir>/gdk
Build dir: <datadir>/gdk/build-clang
Build type: native build
Project name: gdk
Project version: 0.0.54
Sanity testing C compiler: clang
Is cross compiler: False.
Sanity check compiler command line: clang sanitycheckc.c -o sanitycheckc.exe -isysroot /Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -mmacosx-version-min=10.13 -O3
Sanity check compile stdout:

-----
Sanity check compile stderr:
clang: warning: no such sysroot directory: '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk' [-Wmissing-sysroot]
ld: library not found for -lSystem
clang: error: linker command failed with exit code 1 (use -v to see invocation)

-----

meson.build:1:0: ERROR: Compiler clang can not compile programs.

How can I fix this?

[jgriffiths]

The build script does the following for OSX:

if [ \( "$BUILD" = "--clang" \) ]; then
    if [ \( "$(uname)" = "Darwin" \) ]; then
        export XCODE_PATH=$(xcode-select --print-path 2>/dev/null)
        export PLATFORM="MacOSX"
        export SDK_PATH="$XCODE_PATH/Platforms/$PLATFORM.platform/Developer/SDKs/$PLATFORM.sdk"
        export SDK_CFLAGS="$SDK_CFLAGS -isysroot ${SDK_PATH} -mmacosx-version-min=10.13"
        export SDK_LDFLAGS="$SDK_LDFLAGS -isysroot ${SDK_PATH} -mmacosx-version-min=10.13"
        export CFLAGS="${SDK_CFLAGS} -O3"
        export LDFLAGS="${SDK_LDFLAGS}"
    fi
    build clang clang++
fi

So I'd try running xcode-select --print-path and make sure the path it prints exists. If not, you will probably need to install or select the correct installed version of the xcode build tools.

Disclaimer, I'm not familiar with Apple platforms, @lvaccaro may have an idea if this isn't your issue.

[altafan]

@jgriffiths I was finally able to build the python SDK but I had to manually change the SDK_PATH to:

export SDK_PATH="$XCODE_PATH/SDKs/$PLATFORM.sdk"

An even better way to retrieve the SDK path instead of constructing it could be:

export SDK_PATH=$(xcrun --show-sdk-path)

I can eventually open a PR if you think the fix makes sense.

[jgriffiths]

@altafan I you could PR this and cc: @lvaccaro for review that would be great, thanks!

[lvaccaro]

It looks a nice sdk path improvement for the building system. 👍