I'm noticing that |mach artifact install| on macOS is not cleaning up its mounted DMG files, leaving mounted filesystems like: $ mount ... /dev/disk2s3 on /Volumes/Firefox Nightly (hfs, local, nodev, nosuid, read-only, noowners, nobrowse, mounted by nalexander) These are listed as "nobrowse" so they don't show up in the Finder. This could be a little push to get Bug 1253110 across the line, because after that ticket macOS clients would no longer mount DMG files at all during artifact installation.