The current loguru stacktrace configuration in liblsl can cause compilation failures on certain platforms. The relevant code is shown below.

cmake/ProjectOptions.cmake

# Default LSL_DEBUGLOG to ON for Debug builds (single-config generators only)
string(COMPARE EQUAL "${CMAKE_BUILD_TYPE}" "Debug" _LSL_DEBUGLOG_DEFAULT)
option(LSL_DEBUGLOG "Enable (lots of) additional debug messages" ${_LSL_DEBUGLOG_DEFAULT})

cmake/Dependencies.cmake

set_source_files_properties("thirdparty/loguru/loguru.cpp"
        PROPERTIES COMPILE_DEFINITIONS LOGURU_STACKTRACES=$<BOOL:${LSL_DEBUGLOG}>)

thirdparty/loguru/loguru.cpp

#if defined(_WIN32) || defined(__CYGWIN__)
    #define LOGURU_PTHREADS    0
    #define LOGURU_WINTHREADS  1
    #ifndef LOGURU_STACKTRACES
        #define LOGURU_STACKTRACES 0
    #endif
#else
    #define LOGURU_PTHREADS    1
    #define LOGURU_WINTHREADS  0
    #ifdef __GLIBC__
        #ifndef LOGURU_STACKTRACES
            #define LOGURU_STACKTRACES 1
        #endif
    #else
        #ifndef LOGURU_STACKTRACES
            #define LOGURU_STACKTRACES 0
        #endif
    #endif
#endif

#if LOGURU_STACKTRACES
    #include <cxxabi.h>    // for __cxa_demangle
    #include <dlfcn.h>     // for dladdr
    #include <execinfo.h>  // for backtrace
#endif // LOGURU_STACKTRACES

As shown above, LOGURU_STACKTRACES depends on the GNU libc backtrace facility and is therefore not supported on all platforms, notably:

• Windows (MSVC)
• Linux with musl libc (see: https://github.com/ronchaine/libexecinfo)
• Android (see: Android build fails for android when sdk < 33, due to missing symbols in execinfo.h nodejs/node#46952)

Because LSL_DEBUGLOG defaults to ON for Debug builds when using a single-config generator, this forces LOGURU_STACKTRACES to be enabled and causes compilation errors on the platforms listed above.

To illustrate with Windows: when using the default Visual Studio generator (a multi-config generator), CMAKE_BUILD_TYPE is not set to Debug, so the problem does not surface. However, when using the Ninja generator (a single-config generator), the issue is triggered:

cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Debug
cmake --build . --target install

https://github.com/SharpLSL/liblsl-ci-build/tree/loguru-stacktraces

https://github.com/SharpLSL/liblsl-ci-build/actions/runs/24925417393/job/72994456551

A straightforward workaround would be to skip the setting on Windows:

if(NOT WIN32)
    set_source_files_properties("thirdparty/loguru/loguru.cpp"
        PROPERTIES COMPILE_DEFINITIONS LOGURU_STACKTRACES=$<BOOL:${LSL_DEBUGLOG}>)
endif()

However, this still does not address Linux musl libc or Android.

Testing showed that simply removing the set_source_files_properties call works well: loguru's built-in platform detection is already sensible — it defaults LOGURU_STACKTRACES to 0 on Windows and to 1
when __GLIBC__ is defined.

It is also worth noting that loguru only prints a stack trace when LOG_F(FATAL, ...) is called, and liblsl does not currently log anything at the FATAL level.

Given the above, there are several possible approaches:

Option 1: Always disable stacktraces (since liblsl never logs at FATAL level)

set_source_files_properties("thirdparty/loguru/loguru.cpp"
    PROPERTIES COMPILE_DEFINITIONS LOGURU_STACKTRACES=0)

Option 2: Explicitly disable stacktraces when LSL_DEBUGLOG is OFF

if(NOT LSL_DEBUGLOG)
    set_source_files_properties("thirdparty/loguru/loguru.cpp"
        PROPERTIES COMPILE_DEFINITIONS LOGURU_STACKTRACES=0)
endif()

Option 3: Remove the explicit LOGURU_STACKTRACES setting and let
loguru decide

This PR uses Option 3. Other suggestions are welcome.