Compile with -fno-common
https://github.com/ggreer/the_silver_searcher/commit/21eaa1c4160b868b0c5bbf59da17974429f30055

Index: src/util.c
--- src/util.c.orig
+++ src/util.c
@@ -21,6 +21,8 @@
     }                                     \
     return ptr;
 
+FILE *out_fd = NULL;
+ag_stats stats;
 void *ag_malloc(size_t size) {
     void *ptr = malloc(size);
     CHECK_AND_RETURN(ptr)
