NetBSD < 7 doesn't have posix_fallocate See: https://www.netbsd.org/changes/changes-7.0.html
diff --git a/src/posix.c b/src/posix.c
index b5dfac5..32ca704 100644
--- a/src/posix.c
+++ b/src/posix.c
@@ -157,7 +157,7 @@ int p_rename(const char *from, const char *to)
int p_fallocate(int fd, off_t offset, off_t len)
{
-#ifdef __APPLE__
+#if defined (__APPLE__) || (defined (__NetBSD__) && __NetBSD_Version__ < 700000000)
fstore_t prealloc;
struct stat st;
size_t newsize;