Filespecs for flags can't have quotes (and therefore presumably spaces). Eg -o csv:FILENAME, -o json:FILENAME, or -o sh:FILENAME #747

For example:

rmlint /mnt/btrfs/array1 ... -o csv'/home/bill/.local/rmlint/rmlint 2025-06-06 07-35-34.csv' -o json:"/tmp/rmlint $(date "+%Y%m%d-%H%M%S").json"

(The "..." indicates some flags that are or at least seem irrelevant to the issue, as rmlint complains about the arguments to matter where they are in the command or what other arguments are present.)

Obviously in this example, the need for spaces (and therefore single or double quotes) could be obviated by just not using spaces, and something like the tried and true underscore instead.

But I'm trying to wrap this more simply and idiot-proof-ly, to do just one thing, and this seems like a design bug.

In general, any time a linux CLI tool - coreutils or otherwise - accepts a file specification, it should be able to handle it quoted with both single and double quotes. (And to my knowledge pretty much universally does.) Whether a fixed position argument (which rmlint handles), or as a parameter to a flag.