@Tim Edwards has something changed here in Magic? I get the following output now

Bad flatten option "-toplevel";  must start with "-no" or "-do"

When doing

flatten -toplevel ${CELL_NAME}_flat

just

flatten -do-toplevel ${CELL_NAME}_flat

?

Usage:

flatten [option] cellname

where cellname is the name of a cell definition to be created, and into which the flattened geometry will be placed. option may be one of -nolabels, -nosubcircuits, or -noports, -novendor, -dotoplabels, -doproperty, and -dobox.

thank you both, not sure how i didn't notice that before