See https://gitlab.alpinelinux.org/alpine/aports/-/issues/16106

diff -upr cpulimit-0.2.orig/src/process_group.c cpulimit-0.2/src/process_group.c
--- cpulimit-0.2.orig/src/process_group.c	2024-05-12 12:58:16.221876809 +0200
+++ cpulimit-0.2/src/process_group.c	2024-05-12 12:58:26.731904879 +0200
@@ -24,6 +24,7 @@
 #include <limits.h>
 #include <sys/time.h>
 #include <signal.h>
+#include <libgen.h>
 
 #include <assert.h>
 
