Cannot perform readlinkat on the mount namespace file descriptor of the init process

I’m trying to utilize snap to install a program called “anbox,” which is an Android emulator, on PureOS (a derivative of Debian). This is my first time using snap and I recognize PureOS is pretty niche. But I’m running into this error:

~ sudo snap install --devmode --beta anbox                                 
error: cannot perform the following tasks:
- Run install hook of "anbox" snap if present (run hook "install": cannot perform readlinkat() on the mount namespace file descriptor of the init process: Permission denied)

Then when I run dmesg|grep DENIED this is what I see:

[  138.352094] audit: type=1400 audit(1544543062.808:85): apparmor="DENIED" operation="ptrace" profile="/usr/lib/snapd/snap-confine" pid=4173 comm="snap-confine" requested_mask="read" denied_mask="read" peer="unconfined"

I’ve been reading through some other, similar forum posts on here to try and fix things, but it looks like capability sys_ptrace and ptrace trace peer=unconfined are already present in my /etc/apparmor.d/usr.lib.snapd.snap-confine.real file. So I don’t really know what to do.

Here’s the output of running snap --version if it helps:

snap    2.30-5+b1
snapd   2.30-5+b1
series  16
pureos  
kernel  4.18.0-2-amd64