Task description: link
Interesting one. Converting from Snafu to decimal was quite simple. The other way around was tricky. My first idea was to just increment a Snafu number starting from 0 a number of times equal to the decimal value. This was infeasible for the real input value that I had to convert.
While trying to shortcut to a higher starting value to begin incrementing from, my shortcut eventually ended up being the entire function, giving me the final Snafu number. Neat!
I spent 10-20 minutes debugging my correct answer because aocrunner was not sending it correctly. I finally just manually submitted it on the AoC page, and it was indeed correct. Oh well, I've had worse speed bumps this year!