`override` indicates an override of a virtual method and refuses to compile in case of a signature mismatch across the inheritence hierarchy.
This is especially useful when signatures change not to forget anything. Hence, we shall always use `override` whereever applicable.
to stick to CMake pre-v3.29 behavior. CMake v3.29 introduces CPACK_WIX_INSTALL_SCOPE. Its default conflicts with the ALLUSERS property in our icinga-installer/icinga2.wixpatch.cmake.
Unfortunately, the symbol resolution of boost::stacktrace is broken on
FreeBSD, therefore fall back to using backtrace_symbols() to print the
stack trace saved by Boost.
Additionally, -D_GNU_SOURCE is required on FreeBSD for the
_Unwind_Backtrace function used by boost::stacktrace.
Older versions of MSVC fail to rethrow an unhandled C++ exception (using
`throw;`) in the termination handler (`std::set_terminate`), however
Icinga relies on this behavior in its crash handler
(`Application::ExceptionHandler`).
On case-insensitive file systems (i.e. macOS), the VERSION file collides with the Boost-provided version file on #include <version>.
Work around by re-naming VERSION to ICINGA2_VERSION.
When statically compiling icinga2 with a local boost the order of the boost libraries matters.
Correcting the order fixes the following linker issue:
```
make[5]: Entering directory `.../icinga2/icinga2-2.11.3/build'
[ 98%] Linking CXX executable ../Bin/RELEASE/icinga2
.../boost_1_72_0/lib/libboost_coroutine.a(coroutine_context.o): In function `boost::coroutines::detail::coroutine_context::coroutine_context(void (*)(boost::context::detail::transfer_t), boost::coroutines::detail::preallocated const&)':
coroutine_context.cpp:(.text+0x59): undefined reference to `make_fcontext'
.../boost_1_72_0/lib/libboost_coroutine.a(coroutine_context.o): In function `boost::coroutines::detail::coroutine_context::jump(boost::coroutines::detail::coroutine_context&, void*)':
coroutine_context.cpp:(.text+0xe8): undefined reference to `jump_fcontext'
collect2: error: ld returned 1 exit status
make[5]: *** [Bin/RELEASE/icinga2] Error 1
```
Signed-off-by: Sven Nierlein <sven@nierlein.de>
