snapd stalls while doing a remodelling with additional required app snaps

[Alfonso Sanchez-Beato]

While remodelling to

{
    "type": "model",
    "series": "16",
    "authority-id": "<redacted>",
    "brand-id": "<redacted>",
    "model": "ubuntu-core-22-pc-amd64",
    "architecture": "amd64",
    "timestamp": "2022-07-11T19:35:00.0Z",
    "base": "core22",
    "grade": "dangerous",
    "store": "<redacted>",
    "revision": "2",
    "snaps": [
        {
            "name": "iotdevice-abeato2-pc22",
            "type": "gadget",
            "default-channel": "latest/stable",
            "id": "<redacted>"
        },
        {
            "name": "pc-kernel",
            "type": "kernel",
            "default-channel": "22/stable",
            "id": "pYVQrBcKmBa0mZ4CCN7ExT6jH8rY1hza"
        },
        {
            "name": "core22",
            "type": "base",
            "default-channel": "latest/stable",
            "id": "amcUKQILKXHHTlmSa7NMdnXSx02dNeeT"
        },
        {
            "name": "snapd",
            "type": "snapd",
            "default-channel": "latest/stable",
            "id": "PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4"
        },
        {
            "name": "bluez",
            "type": "app",
            "default-channel": "20/stable",
            "id": "JmzJi9kQvHUWddZ32PDJpBRXUpGRxvNS"
        }
    ]
}

from a UC20 system, snapd got stalled while "ensuring prerequisites for bluez". Removing that snap moved things forward. See attached file with backtrace.

[Michael Vogt (mvo)]

I wonder if it could be a circular wait we setup in one of the tasks.