ostree admin instutil set-karg error attempting to remove booted deployment

[Chris Murphy <lists colorremedies com>]

[chris@localhost ~]$ sudo ostree admin instutil set-kargs -v
--append=systemd.mask=alsa-state
OT: Deployment 6dc795302af832537ad225050a00441726350937f4f9b218b01f5e885c0e1619.0
unlocked=0
error: Attempting to remove booted deployment

[chris@localhost ~]$ sudo ostree admin instutil set-kargs -v
--import-proc-cmdline
OT: Deployment 6dc795302af832537ad225050a00441726350937f4f9b218b01f5e885c0e1619.0
unlocked=0
error: Attempting to remove booted deployment

*shrug*

The error is confusing because I'm not asking for it to remove a
booted deployment, so why does it fail in the attempt? I just want it
to update kernel arguments with an append.

Figured I'd ask before filing a bug.

-- 
Chris Murphy