Maxperson
Morkus from Orkus
See, I'm not going to call for a roll for that.Sometimes the safe just can't be opened by the rogue. But until they try, I'm not going to reveal that information. After they fail, I'll use their result to determine if they know it's impossible.
DM: "Okay. You want to open the safe, give me a thieves' tools roll to see if you can.
Rogue: "8"
DM: "You don't succeed. Do you want to keep trying?"
Rogue: "9 rolls later, 18! Finally a good number."
DM: "You fail and learn that you can't succeed."
Now you've(general you) wasted a chunk of limited play time on something that really didn't matter. Instead I'd say something like.
DM: "Okay. You want to open the safe. How long are you going to spend trying to get it open?"
Rogue: "5 minutes seems safe. Pun intended. Haha!"
DM: "Very funny. After 2 minutes of trying, you're certain that this safe is beyond your ability."
That entire exchange would happen in less time than it would take for the player to register a request to roll, pick up the die, roll it, and read me a number to see if he figures out that he can't open the safe. Let alone all the other exchanges in your method where you continue to describe failure and ask for more rolls until he rolls well enough to figure it out.