Failed to run build script for part in Snapcraft

Question

I am trying to build my flutter app with snapcraft and I keep getting this error

CRAFT_ARCH_TRIPLET is deprecated, use CRAFT_ARCH_TRIPLET_BUILD_{ON|FOR}
CRAFT_ARCH_TRIPLET is deprecated, use CRAFT_ARCH_TRIPLET_BUILD_{ON|FOR}
CRAFT_ARCH_TRIPLET is deprecated, use CRAFT_ARCH_TRIPLET_BUILD_{ON|FOR}
CRAFT_ARCH_TRIPLET is deprecated, use CRAFT_ARCH_TRIPLET_BUILD_{ON|FOR}
Launching instance...
Creating new instance from remote
Creating new base instance from remote
^@^@Creating new instance from base instance
Starting instance
Failed to run the build script for part 'appName'.                            
Failed to execute pack in instance.
Recommended resolution: Run the same command again with --debug to shell into the environment if you wish to introspect this failure.

I am running the command snapcraft --use-lxd --bind-ssh on a ubuntu-2004:202104-01 machine and this is my snapcraft.yaml file

    name: appName
    base: core22 # the base snap is the execution environment for this snap
    version: '1.0.1' # just for humans, typically '1.2+git' or '1.3.2'
    summary: AppName # 79 char long summary
    description: |
      Your business, simplified

    grade: devel # must be 'stable' to release into candidate/stable channels
    confinement: devmode # use 'strict' once you have the right plugs and slots

    slots:
      dbus-appname: # adjust accordingly to your app name
        interface: dbus
        bus: session
        name: io.appcomp.appname # adjust accordingly to your app name and

    apps:
      appname:
        command: appname
        extensions: [gnome] # gnome includes the libraries required by flutter
        plugs:
          - network
        slots:
          - dbus-appname

    parts:
      appame:
        # See 'snapcraft plugins'
        plugin: flutter
        source: .
        flutter-target: lib/main.dart