juju deploy is too slow

Deploying a local .charm takes more than 1 minute:

$ time juju deploy --debug ./lxd-cloud-cell_ubuntu-22.04-amd64.charm cell-a --resource snap=lxd-cloud-cell_0+git.d27fa0c_amd64.snap -n 3 --to 31,34,35
12:49:08 INFO juju.cmd supercommand.go:56 running juju [2.9.33 95186b2e0c2dfa9fe7b0b815cfe2c939813f9302 gc go1.18.3]
12:49:08 DEBUG juju.cmd supercommand.go:57 args: []string{"/snap/juju/20277/bin/juju", "deploy", "--debug", "./lxd-cloud-cell_ubuntu-22.04-amd64.charm", "cell-a", "--resource", "snap=lxd-cloud-cell_0+git.d27fa0c_amd64.snap", "-n", "3", "--to", "31,34,35"}
12:49:08 INFO juju.juju api.go:78 connecting to API addresses: [172.17.40.184:17070]
12:49:08 DEBUG juju.api apiclient.go:1153 successfully dialed "wss://172.17.40.184:17070/api"
12:49:08 INFO juju.api apiclient.go:688 connection established to "wss://172.17.40.184:17070/api"
12:49:08 INFO juju.juju api.go:78 connecting to API addresses: [172.17.40.184:17070]
12:49:08 DEBUG juju.api apiclient.go:1153 successfully dialed "wss://172.17.40.184:17070/model/6fec25fe-a09f-4764-8b80-c43f1a62f73c/api"
12:49:08 INFO juju.api apiclient.go:688 connection established to "wss://172.17.40.184:17070/model/6fec25fe-a09f-4764-8b80-c43f1a62f73c/api"
12:49:13 DEBUG juju.core.charm computedseries.go:27 series "jammy" for charm "lxd-cloud-cell" with format 2, Kubernetes false
12:49:13 INFO juju.cmd.juju.application.deployer series_selector.go:83 with the configured model default series "jammy"
12:49:13 DEBUG juju.core.charm computedseries.go:27 series "jammy" for charm "lxd-cloud-cell" with format 2, Kubernetes false
12:49:13 INFO cmd charm.go:384 Preparing to deploy local charm: "lxd-cloud-cell_ubuntu-22.04-amd64.charm"
12:50:17 INFO cmd charm.go:406 Located local charm "lxd-cloud-cell", revision 13
12:50:23 INFO cmd charm.go:236 Deploying "cell-a" from local charm "lxd-cloud-cell", revision 13 on jammy
12:50:25 DEBUG juju.api monitor.go:35 RPC connection died
12:50:25 DEBUG juju.api monitor.go:35 RPC connection died
12:50:25 INFO cmd supercommand.go:544 command finished

real 1m17.398s
user 0m3.883s
sys 0m6.742s

Both local files are small:

$ ll -h lxd-cloud-cell_ubuntu-22.04-amd64.charm lxd-cloud-cell_0+git.d27fa0c_amd64.snap
-rw-rw-r-- 1 sdeziel sdeziel 20M Aug 2 22:02 lxd-cloud-cell_0+git.d27fa0c_amd64.snap
-rw-r--r-- 1 sdeziel sdeziel 5.8M Aug 17 19:17 lxd-cloud-cell_ubuntu-22.04-amd64.charm

And the juju controller is a local LXD instance on the same machine so the network is rather fast:

$ lxc ls
+---------------+---------+----------------------+------+-----------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+---------------+---------+----------------------+------+-----------+-----------+
| juju-492fcd-0 | RUNNING | 172.17.40.184 (eth0) | | CONTAINER | 0 |
+---------------+---------+----------------------+------+-----------+-----------+

$ ping 172.17.40.184
PING 172.17.40.184 (172.17.40.184) 56(84) bytes of data.
64 bytes from 172.17.40.184: icmp_seq=1 ttl=64 time=0.089 ms
64 bytes from 172.17.40.184: icmp_seq=2 ttl=64 time=0.090 ms
^C
--- 172.17.40.184 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1008ms
rtt min/avg/max/mdev = 0.089/0.089/0.090/0.000 ms

Juju probably doesn't use the LXD file transfer facility but here are some numbers for comparison:

$ time lxc file push lxd-cloud-cell_ubuntu-22.04-amd64.charm juju-492fcd-0/tmp/

real 0m2.910s
user 0m0.115s
sys 0m0.158s

$ time lxc file push lxd-cloud-cell_0+git.d27fa0c_amd64.snap juju-492fcd-0/tmp/

real 0m1.220s
user 0m0.121s
sys 0m0.211s

After calling `juju deploy`, there appears to be a ~1 minute "pause" which probably corresponds to:

12:49:13 INFO cmd charm.go:384 Preparing to deploy local charm: "lxd-cloud-cell_ubuntu-22.04-amd64.charm"
12:50:17 INFO cmd charm.go:406 Located local charm "lxd-cloud-cell", revision 13

Additional information:

$ lsb_release -rd
Description: Ubuntu 20.04.4 LTS
Release: 20.04
$ uname -a
Linux shell01 5.19.2+ #50 SMP Sat Aug 20 02:52:38 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux
$ snap list juju lxd
Name Version Rev Tracking Publisher Notes
juju 2.9.33 20277 latest/stable canonical✓ classic
lxd 5.4-1ff8d34 23371 latest/stable canonical✓ -