https://github.com/tpoechtrager/osxcross provides a cross compiling toolchain to build from linux for osx.
In principle a very tempting approach, but it will require some work.
I managed to get the crosscompiler working, but not much else.
For building KAsync:
I tried getting qt using the builtin macports, which worked, but lacked qtest.
After commenting qtest I ended up with moc not being found:
```
[I] _> ~/o/o/s/k/build on master make
Scanning dependencies of target KAsync_autogen
[ 16%] Automatic MOC for target KAsync
Generating MOC source EWIEGA46WW/moc_future.cpp
Permission denied
AutoMoc: Error: moc process failed for
"EWIEGA46WW/moc_future.cpp"
AutoMoc: Command:
/opt/local/libexec/qt5/bin/moc -I/home/mollekopf/osxcross/osxcross/src/kasync/build/src -I/home/mollekopf/osxcross/osxcross/src/kasync/build/src/KAsync_autogen/include -I/home/mollekopf/osxcross/osxcross/src/kasync/src -I/opt/local/libexec/qt5/lib/QtCore.framework -I/opt/local/libexec/qt5/lib/QtCore.framework/Headers -I/opt/local/libexec/qt5/./mkspecs/macx-clang -F /opt/local/libexec/qt5/lib -DQT_CORE_LIB -DQT_MAC_USE_COCOA -DQT_NO_CAST_FROM_ASCII -DQT_NO_CAST_FROM_BYTEARRAY -DQT_NO_CAST_TO_ASCII -DQT_NO_DEBUG -DQT_NO_SIGNALS_SLOTS_KEYWORDS -DQT_NO_URL_CAST_FROM_STRING -DQT_USE_FAST_OPERATOR_PLUS -DQT_USE_QSTRINGBUILDER -D_DARWIN_C_SOURCE -D_LARGEFILE64_SOURCE -o /home/mollekopf/osxcross/osxcross/src/kasync/build/src/KAsync_autogen/EWIEGA46WW/moc_future.cpp /home/mollekopf/osxcross/osxcross/src/kasync/src/future.h
AutoMoc: Command output:
make[2]: *** [src/CMakeFiles/KAsync_autogen.dir/build.make:58: src/CMakeFiles/KAsync_autogen] Error 1
make[1]: *** [CMakeFiles/Makefile2:156: src/CMakeFiles/KAsync_autogen.dir/all] Error 2
make: *** [Makefile:141: all] Error 2
```
Some further notes:
```
Minimum OSX is 10.11 (given by xcode 7.3.1) aka darwin 14
git clone https://github.com/tpoechtrager/osxcross.git
cd osxcross
tools/gen_sdk_package_darling_dmg.sh ../Xcode_7.3.1.dmg
mv MacOSX10.11.sdk.tar.xz tarballs/
./build.sh (accept everything)
add /home/mollekopf/osxcross/osxcross/target/bin to $PATH
export MACOSX_DEPLOYMENT_TARGET=10.11
osxcross-macports install pstree
Fix the symlinks for the .cmake files in macports:
sudo ln -s /home/mollekopf/osxcross/osxcross/target/macports/pkgs/opt/local /opt/local
ls -l macports/pkgs/opt/local/lib/cmake/Qt5/Qt5Config.cmake
```
Some potentially useful related links:
https://github.com/trezor/trezord/blob/master/CMakeLists.txt
https://github.com/tpoechtrager/osxcross/issues/80
https://github.com/macports/macports-ports/blob/master/mail/gnupg2/Portfile
https://github.com/jpochyla/macdylibbundler/tree/b85856c133d0b4794b540641646e22911ab6c537