Thanks @casey, this looks great.

@casey I'm getting a weird behavior when using ~

just --tempdir=~/tmp foo
error: Recipe `foo` could not be run because of an IO error while trying to create a temporary directory or write a file to that directory: No such file or directory (os error 2) at path "/home/myredacteduser/dev/~/tmp/just-3FlApn"

But this works:

$ mkdir tmp
$ just --tempdir=tmp foo

Maybe --tempdir should take an absolute path.

@kenden ~ is expanded by the shell, and is only expanded if it is the first character of a whitespace-delimited word. Try this:

just --tempdir ~/tmp foo

@casey thanks, I didn't know ~ / tilde is only expanded if it is the first character of a whitespace-delimited word.
It works 👍