Confirmed:
```
sqlite> create table t2 (sz int, constraint t2_sz_fk foreign key('size', sz) references enum(cat, val));
Error: unknown column "size" in foreign key definition
```
Confirmed:
```
sqlite> create table t2 (sz int, constraint t2_sz_fk foreign key('size', sz) references enum(cat, val));
Error: unknown column "size" in foreign key definition
```