debug: enable compilation without execinfo.h

Otherwise, the CI breaks, as Alpine does not have execinfo anymore. If
not present, we cannot generate a backtrace, so we just print that.

.github/workflows/ci.yaml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     container: alpine:edge
     steps:
-    - run: apk --no-cache add git gcc g++ binutils pkgconf meson ninja musl-dev wayland-dev wayland-protocols libinput-dev libevdev-dev libxkbcommon-dev pixman-dev glm-dev libdrm-dev mesa-dev cairo-dev pango-dev eudev-dev libxml2-dev libexecinfo-dev libseat-dev libxcb-dev xcb-util-wm-dev xwayland doctest doctest-dev cmake
+    - run: apk --no-cache add git gcc g++ binutils pkgconf meson ninja musl-dev wayland-dev wayland-protocols libinput-dev libevdev-dev libxkbcommon-dev pixman-dev glm-dev libdrm-dev mesa-dev cairo-dev pango-dev eudev-dev libxml2-dev libseat-dev libxcb-dev xcb-util-wm-dev xwayland doctest doctest-dev cmake
     - uses: actions/checkout@v1
     - run: git config --global --add safe.directory /__w/wayfire/wayfire
     - run: git submodule sync --recursive && git submodule update --init --force --recursive

src/debug.cpp

@@ -2,15 +2,20 @@
 #include <wayfire/debug.hpp>
 #include <sstream>
 #include <iomanip>
-#include <execinfo.h>
-#include <cxxabi.h>
+
+#if __has_include(<execinfo.h>)
+    #include <execinfo.h>
+    #include <cxxabi.h>
+#endif
+
 #include <cstdio>
 #include <dlfcn.h>
 #include <sys/stat.h>
 
 #define MAX_FRAMES 256
 #define MAX_FUNCTION_NAME 1024
 
+#if __has_include(<execinfo.h>)
 struct demangling_result
 {
     std::string executable;
@@ -254,6 +259,15 @@ void wf::print_trace(bool fast_mode)
     free(symbollist);
 }
 
+#else // has <execinfo.h>
+void wf::print_trace(bool)
+{
+    LOGE("Compiled without execinfo.h, cannot provide a backtrace!",
+        " Try using address sanitizer.");
+}
+
+#endif
+
 /* ------------------- Impl of debugging functions ---------------------------*/
 #include <iomanip>
 std::ostream& operator <<(std::ostream& out, const glm::mat4& mat)