os_type unix soname_pattern_base "libbotan-{version_major}.{version_minor}.so" soname_pattern_abi "libbotan-{version_major}.{version_minor}.so.{abi_rev}" soname_pattern_patch "libbotan-{version_major}.{version_minor}.so.{abi_rev}.{version_patch}" clock_gettime gettimeofday posix_mlock gmtime_r dlopen readdir