Output is contaminated with control character when piped into pbcopy

[ikanago]

This occurs only when the binary is executed without args; interactive mode.
Result of omekasy | hexyl:

┌────────┬─────────────────────────┬─────────────────────────┬────────┬────────┐
│00000000│ 1b 5b 35 44 1b 5b 32 4b ┊ f0 9d 92 82 f0 9d 92 83 │•[5D•[2K┊××××××××│
│00000010│ f0 9d 92 84 0d 0a 1b 5b ┊ 4a                      │××××__•[┊J       │
└────────┴─────────────────────────┴─────────────────────────┴────────┴────────┘