Try a hopefully more portable definition of ZIP_INT64_MAX.

cmake-zipconf.h.in

diff --git a/cmake-zipconf.h.in b/cmake-zipconf.h.in
index 876568c..17edc6c 100644
--- a/cmake-zipconf.h.in
+++ b/cmake-zipconf.h.in
@@ -114,7 +114,7 @@
 #define ZIP_INT32_MAX	 0x7fffffffL
 #define ZIP_UINT32_MAX	 0xffffffffLU
 
-#define ZIP_INT64_MIN	-0x8000000000000000LL
+#define ZIP_INT64_MIN	 (-ZIP_INT64_MAX-1LL)
 #define ZIP_INT64_MAX	 0x7fffffffffffffffLL
 #define ZIP_UINT64_MAX	 0xffffffffffffffffULL