Backtracing assumes first form can learn TM/HM move

[Butterfree]

If you click the backtrace icon from a Pokémon that can learn a TM when its pre-evolved form can not learn it, the chain shown will display Pokémon that can learn the TM and breed with the Pokémon, even if the move can clearly never be bred onto that Pokémon because its pre-evolution can't learn the TM and thus won't inherit the move.

Example: Eevee cannot learn the Thunderbolt TM (TM24), while Jolteon can. From Jolteon's page, I can click the backtrace icon on the Thunderbolt TM and get suggestions for breeding chains which would work if only Eevee could ever inherit Thunderbolt, but it can't. Of course, this most likely also happens with Pokémon where it is less obvious that the baby can't learn the relevant TM, possibly screwing up people's team plans if they trust the backtracer without a second thought. You should make the backtracer look for moves the lowest-form evolutions of the chain can learn (both lowest forms, of course, in the case of two possible babies).

[eevee]

This has been fixed by #302, in which I made the concept of target Pokemon a little less ambiguous and actually search the chain for possible eggs.