The problem. I formatted a USB stick to ext4. The stick was 32GB. So one might think that format will take a while. But, still, formatting - at least when FAT32? - can be quick. This format was slow - so slow, that I considered removing drive. I thought the formatting had hung. But then the formatting completed.
The solution: have the formatter show more than a busy-type indicator. That is, have it show a percentage or something like that (and the indicator need not be very accurate). It's true that a drive reporting that it is X% formatted might still have hung, but if one can see progress - X%, then X+Y% - one is less likely to be misled. Still, perhaps the low-level formatting process does not give much data about progress. In that case, perhaps mintstick could estimate, in advance, the likely time, and then do something, indicator wise, with that (well, with that and the elapsed time).
mintstick 1.6.2