$ man dash ... file1 -nt file2 True if file1 and file2 exist and file1 is newer than file2. $ man bash ... file1 -nt file2True if file1 is newer (according to modification date) than file2, or if file1 exists and file2 does not.
That's it!
I don't know which one doesn't follow the right standard.
man test states the same as bash, as is ksh btw. So dash is wrong.
However, Helmut, your proposition to add -o ! -f will do the trick in any case.
Sure, but it is slow because it tests all files first (on first make). Maybe I'll think of a better solution.
-- Helmut Karlowski