Stack size at least 8MB on libmusl. (#4528)

lib/Basics/ArangoGlobalContext.cpp

@@ -140,6 +140,20 @@ ArangoGlobalContext::ArangoGlobalContext(int argc, char* argv[],
           TRI_GetInstallRoot(TRI_LocateBinaryPath(argv[0]), InstallDirectory)),
       _ret(EXIT_FAILURE),
       _useEventLog(true) {
+#ifndef _WIN32
+#ifndef __APPLE__
+#ifndef __GLIBC__
+  // Increase default stack size for libmusl:
+  pthread_attr_t a;
+  memset(&a, 0, sizeof(pthread_attr_t));
+  pthread_attr_setstacksize(&a, 8*1024*1024);  // 8MB as in glibc
+  pthread_attr_setguardsize(&a, 4096);         // one page
+  pthread_setattr_default_np(&a);
+#endif
+#endif
+#endif
+
+
   // allow failing memory allocations for the global context thread (i.e. main program thread)
   TRI_AllowMemoryFailures();