ERROR: ./ivltests/pr2800985b.v:11: $ferror's fd (first) argument must be numeric.
ERROR: ./ivltests/pr2800985b.v:12: $ferror requires a second (register) argument.
ERROR: ./ivltests/pr2800985b.v:13: $ferror's second argument must be a reg (>=640 bits).
ERROR: ./ivltests/pr2800985b.v:14: $ferror's second argument must have 640 bit or more.
ERROR: ./ivltests/pr2800985b.v:15: $ferror takes two arguments.
                                   Found 1 extra argument.