Gentoo issue: https://bugs.gentoo.org/900148

diff -Naur a/app/core/gimpbacktrace-linux.c b/app/core/gimpbacktrace-linux.c
--- a/app/core/gimpbacktrace-linux.c
+++ b/app/core/gimpbacktrace-linux.c
@@ -39,7 +39,11 @@
 #include <fcntl.h>
 #include <dirent.h>
 #include <signal.h>
-#include <execinfo.h>
+
+#ifdef __GLIBC__
+  #include <execinfo.h>
+#endif
+
 #include <dlfcn.h>
 #include <string.h>
 #include <stdio.h>