> Shouldn't make-temp-file-internal return a non predictable file name?
Nope. It's less predictable but it's still predictable.
> Otherwise what's the point of using make-temp-file in the first place if
> the temporary name is predictable?
`make-temp-name` uses `O_EXCL | O_CREAT` so as to close the race
condition: if someone predicated the filename, we detect it atomically
and we try again.
You might like to check
https://wiki.sei.cmu.edu/confluence/display/c/FIO21-C.+Do+not+create+temporary+files+in+shared+directories
-- Stefan
