Failed to generate snap metadata

Hi there,

I have a question about building a snap package. I am currently using the Ubuntu 18.04 operating system. I already have a manifest with the content of Leafpad, but when I try to build the package I get the following error message:

Failed to generate snap metadata: Specified command ‘leafpad’ was not found. Verify that command is correct and for a more deterministic outcome, specify the relative path to the command from the prime directory.

Manifest:

name: leafpad
version: 0.74-svn
summary: leafpad
description: | leafpad is a simple GTK+ text editor that emphasizes simplicity. As development focus on keeping weight down to a minimum, only the most essential features are implemented inthe editor. Leafpad is simple to use, is easily compiled, required few libraries, and starts up quickly.

confinement: devmode
base: core18

parts: leafpad: plugin: dump source-type: tar source: http://download.savannah.gnu.org/releases/leafpad/leafpad-0.7.6.tar.gz build-packages: - g++ - make - libsdl1.2-dev - libpng-dev - libsdl-net1.2-dev - libsdl-sound1.2-dev - libasound2-dev stage-packages: - libsdl-sound1.2 - libsdl-net1.2 - libxcursor1 - libxi6 - libxinerama1 - libxrandr2 - libxrender1 - libopenal1 - libsndio6.1 - libspeex1 - libvorbisfile3 - libwayland-client0 - libwayland-cursor0 - libwayland-egl1-mesa - libxkbcommon0 - libglu1-mesa - libasound2 - libasyncns0 - libbsd0 - libcaca0 - libdbus-1-3 - libflac8 - libgcc1 - libgcrypt20 - libgl1 - libglvnd0 - libglx0 - libgpg-error0 - liblz4-1 - liblzma5 - libncursesw5 - libogg0 - libpng16-16 - libpulse0 - libsdl1.2debian - libslang2 - libsndfile1 - libstdc++6 - libsystemd0 - libtinfo5 - libvorbis0a - libvorbisenc2 - libwrap0 - libx11-6 - libxau6 - libxcb1 - libxdmcp6 - libxext6 - zlib1g

apps: leafpad: command: leafpad environment: LD_LIBRARY_PATH: $SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/pulseaudio DISABLE_WAYLAND: '1'