Trying to re-install multiple packages with ` snap install` fails with `install/refresh information results from the store`

Ubuntu 21.04 snap 2.50.1:

sudo snap set system experimental.parallel-instances=true
sudo snap install hello-world hello-world_foo

works fine (I wish the parallel setting wasn’t required though, otherwise fails, but not the main point of this thread).

But then if I re-run:

sudo snap install hello-world hello-world_foo

it fails with:

error: cannot install "hello-world", "hello-world_foo": no install/refresh information results from
       the store

and exit status 1.

Idempotency would be really useful while I develop my setup scripts, of which snap is just one step, so I can just re-run install multiple times without checking to skip.

This problem only happens if I run the command with two or more pre-installed packages, re-running:

sudo snap install hello-world

fails gracefully with status 0 as desired:

snap "hello-world" is already installed, see 'snap help refresh'

We agree, and we try to make the snap install command specifically idempotent, it sounds like this is a bug when you have more than one snap specified specifically. Can you file a bug about this on ?