procutil: avoid use of deprecated tempfile.mktemp() In the previous version, I used tempfile.mktemp() because it seemed to be the only way to open a file from two processes (the Python documentation says the file backing NamedTemporaryFile can’t be opened a second time on Windows). However, it’s possible when passing the O_TEMPORARY flag to the second open. Source: https://stackoverflow.com/a/15235559/6366251