Path for desktop launch "does not exist": Building from .deb

snapcraft
5

I’ve made some progress in building this snap but run into an odd situation wherein build.snapcraft.io is reporting the following when attempting to build the snap:

Priming my-part
The path 'prime/usr/share/applications/IBMNotes9.0.desktop' set for 'desktop' in 'ibmnotes' does not exist.
Build failed

Here’s a copy of my current .yaml:

name: ibm-notes
version: 9.0.1.2
summary: IBM Notes is an email client 
description: |
   IBM Notes is the email client software of the IBM Notes and Domino client/server platform. It provides email, calendar and contact management capabilities, but because it works with the Domino server, it can also integrate IBM collaboration tools and business applications.
grade: devel
confinement: devmode

parts:
  my-part:
    plugin: dump
    source: https://fabricsre.bigtester.org/index.php/s/D20mKKg5WD2mKsu/download
    source-type: deb
    build-packages:
      - execstack
    prepare: |
      sed -i 's|Icon=notes|Icon=/opt/ibm/notes/notes\.png|' usr/share/applications/IBMNotes9.0.desktop
      execstack --clear-execstack opt/ibm/notes/notes
    after: [desktop-gtk3]
    prime: [-*]
    
apps:
  ibmnotes: 
    desktop: usr/share/applications/IBMNotes9.0.desktop
    command: bin/desktop-launch $SNAP/opt/ibm/notes/notes
    plugs: 
      - unity7
      - x11
      - home
      - network
      - network-bind
      - gsettings  
      - browser-support
      - opengl
      - pulseaudio
      - wayland

You’ll notice there aren’t any stage-packages yet as I’m trying to get the first part to complete.

I’ve never built a snap from a .deb before, so this is new for me.

Any and all help is much appreciated!