libcxathrow: Fix build on Musl

CHANGELOG.md

@@ -3,6 +3,7 @@
 - Update API level to Oct. 16 2024
 - Fix adding newline at the end for formatting
 - Fixed types of cmake_subprojectoptions::append_link_args
+- Fixed compilation under Musl
 
 # 4.3.4 (Sep 01 2024)
 - Fix crash if first statement of root meson.build is not a function call (#135)

src/libcxathrow/meson.build

@@ -17,7 +17,11 @@ if cxx.get_id() == 'gcc'
         src_files += 'backtrace_stacktrace.cpp'
         cxathrow_deps += backtrace_dep
     else
-        if is_static or host_machine.system() == 'windows'
+        if not cxx.has_header('execinfo.h')
+            # Musl libc doesn't have execinfo.h
+            src_files += null_backtrace
+            used_libunwind = libunwind_dep.found()
+        elif is_static or host_machine.system() == 'windows'
             # Should only happen in crappy distributions....
             src_files += null_backtrace
             used_libunwind = true