Fix implicit declaration of functions. https://github.com/alranel/Crypt-GCrypt/pull/4 --- Makefile.PL.orig 2013-05-25 12:07:14.000000000 -0500 +++ Makefile.PL 2022-01-05 06:49:14.000000000 -0600 @@ -41,6 +41,7 @@ # SHA-512) check_lib_or_exit( function => 'if (gcry_check_version("1.3.0")) return 0; else return 1;', + header => 'gcrypt.h', lib => [qw(gcrypt)], libpath => $gcrypt_libpath );