Robert P. Day removed 8 gazillion occurrences of "extern" on function
definitions.  (That should only be on prototypes.)
diff --git a/archival/libunarchive/get_header_tar_gz.c b/archival/libunarchive/get_header_tar_gz.c
index 9c708a9..62df7b2 100644
--- a/archival/libunarchive/get_header_tar_gz.c
+++ b/archival/libunarchive/get_header_tar_gz.c
@@ -19,7 +19,7 @@
 #include "libbb.h"
 #include "unarchive.h"
 
-extern char get_header_tar_gz(archive_handle_t *archive_handle)
+char get_header_tar_gz(archive_handle_t *archive_handle)
 {
 	unsigned char magic[2];