Comment 6 for bug 1852518

So in my (parallel) debugging it seems to me that notification from udev that processing of the new device is not getting through. If you let kpartx -sav hang in one window and run "dmsetup udevcomplete_all" in another, the kpartx completes successfully.

The notification is supposed to be being sent by the "dmsetup udevcomplete" command in 95-dm-notify.rules. udev seems to _say_ it's running this rule:

dm-0: /usr/lib/udev/rules.d/95-dm-notify.rules:12 RUN '/sbin/dmsetup udevcomplete $env{DM_COOKIE}'

appears in systemd-udevd --debug output, but when I hack the rule to have side effects, it's clearly not being run (it _is_ run when you run kpartx -d). So why would udev print the above line but not actually run the command?