https://bugs.gentoo.org/895842#c6
diff '--color=auto' -burN premake-core-5.0.0-beta2-orig/contrib/libzip/config.h premake-core-5.0.0-beta2/contrib/libzip/config.h
--- premake-core-5.0.0-beta2-orig/contrib/libzip/config.h	2022-09-02 21:11:21.000000000 +0200
+++ premake-core-5.0.0-beta2/contrib/libzip/config.h	2024-05-17 14:07:31.072971328 +0200
@@ -25,6 +25,7 @@
 #endif
 /* #undef HAVE_STRINGS_H */
 /* #undef HAVE_UNISTD_H */
+#define HAVE_UNISTD_H 1
 #define __INT8_LIBZIP 1
 #define INT8_T_LIBZIP 1
 #define UINT8_T_LIBZIP 1
diff '--color=auto' -burN premake-core-5.0.0-beta2-orig/contrib/libzip/mkstemp.c premake-core-5.0.0-beta2/contrib/libzip/mkstemp.c
--- premake-core-5.0.0-beta2-orig/contrib/libzip/mkstemp.c	2022-09-02 21:11:21.000000000 +0200
+++ premake-core-5.0.0-beta2/contrib/libzip/mkstemp.c	2024-05-17 14:07:31.073971328 +0200
@@ -31,6 +31,8 @@
  * SUCH DAMAGE.
  */
 
+#include "zipint.h"
+
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -43,13 +45,14 @@
 #endif
 #include <stdio.h>
 #include <stdlib.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
 
-
-
 int
 _zip_mkstemp(char *path)
 {
diff '--color=auto' -burN premake-core-5.0.0-beta2-orig/contrib/libzip/zip_fdopen.c premake-core-5.0.0-beta2/contrib/libzip/zip_fdopen.c
--- premake-core-5.0.0-beta2-orig/contrib/libzip/zip_fdopen.c	2022-09-02 21:11:21.000000000 +0200
+++ premake-core-5.0.0-beta2/contrib/libzip/zip_fdopen.c	2024-05-17 14:06:29.441972020 +0200
@@ -31,11 +31,10 @@
   IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-
-
 #include "zipint.h"
-
-
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 
 ZIP_EXTERN struct zip *
 zip_fdopen(int fd_orig, int _flags, int *zep)