The web extension is just a wrapper around lesspass-pure on npm
node --version: v10.15.0 yarn --version: v1.16.0
untar src and install dependencies
yarn install
./bin/build_web_extensions
cd packages/lesspass-web-extension/build
find . -type f -exec md5sum {} \;
yarn install
yarn workspace lesspass-pure run build
find packages/lesspass-web-extension/extension/dist/ -type f -exec md5sum {} \;
find packages/lesspass-pure/dist -type f -exec md5sum {} \;