ccache @4.0: error: use of undeclared identifier 'CLONE_NOOWNERCOPY'

[chrstphrchvz (Christopher Chavez)]

​Build fails on macOS 10.12. During configuration, sys/clonefile.h is detected:

-- Looking for sys/clonefile.h
-- Looking for sys/clonefile.h - found

…but fails to compile:

[ 60%] Building CXX object src/CMakeFiles/ccache_lib.dir/cleanup.cpp.o
cd /opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_ccache/ccache/work/build/src && /usr/bin/clang++ -DUSE_XXH_DISPATCH -DXXH_STATIC_LINKING_ONLY -I/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_ccache/ccache/work/build -I/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_ccache/ccache/work/ccache-4.0/src/. -isystem /opt/local/include -pipe -Os -DNDEBUG -I/opt/local/include -stdlib=libc++ -arch x86_64 -mmacosx-version-min=10.12 -Wdouble-promotion -std=c++11 -o CMakeFiles/ccache_lib.dir/cleanup.cpp.o -c /opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_ccache/ccache/work/ccache-4.0/src/cleanup.cpp
/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_ccache/ccache/work/ccache-4.0/src/Util.cpp:259:44: error: use of undeclared identifier 'CLONE_NOOWNERCOPY'
  if (clonefile(src.c_str(), dest.c_str(), CLONE_NOOWNERCOPY) != 0) {
                                           ^

CLONE_NOOWNERCOPY was introduced in macOS 10.13; not sure if it can be used at all on 10.12, or if ccache should instead pretend sys/clonefile.h isn't available on 10.12 and use its fallback implementation in this case.

This is separate from the issue in #61347, since sys/clonefile.h is correctly not detected on macOS 10.11 and earlier.

[ryandesign (Ryan Carsten Schmidt)]

Filed upstream: ​https://github.com/ccache/ccache/issues/688

[ryandesign (Ryan Carsten Schmidt)]

In e50074d719c4b850c5dc6e467d20275b8ffd4872/macports-ports (master):

ccache: Fix build on macOS 10.12

Closes: #61349