Thanks for the report, fixed in 0.3.3
Looks like when I was partway through updating this to 2.1, I moved onto something else and forgot to remove the debug prints, oops.
As a side note, this has also led me to rediscover a bug I forgot about, shotgun building ghost tiles on top of other mineable tiles (e.g. concrete on top of brick) will void the existing tile, as there is a bug in the API preventing my method of mining and spilling the existing tile before placing the new one. Hopefully that will be fixed soon and I won't have to change anything, otherwise I'm either going to have to write a lot of code to simulate tile mining results or do shenanigans with having the player mine it and fishing it back out of their inventory.
