lib/backup-find.c include xalloc.h and invokes xalloc_die(). Therefore:
2019-01-04 Bruno Haible <br...@clisp.org>
backupfile: Fix module dependencies.
* modules/backupfile (Depends-on): Add 'xalloc'.
diff --git a/modules/backupfile b/modules/backupfile
index 4ada3f5..5dcf6c7 100644
--- a/modules/backupfile
+++ b/modules/backupfile
@@ -21,6 +21,7 @@ renameatu
readdir
stdbool
stdint
+xalloc
configure.ac:
gl_BACKUPFILE
