(SP/Propel) Support Tip: Theme customization fails for the manual procedure on Propel 2.20

Error Message

[propel@xxxxxxxxx launchpad]$ gulp dist
[19:44:35] Using gulpfile /opt/hp/propel/launchpad/gulpfile.js
[19:44:35] Starting 'locales.dist'...
[19:44:36] Starting 'assets.dist'...
[19:44:36] Starting 'clean.dist.js'...
[19:44:36] Starting 'clean.dist.styles'...
[19:44:36] Finished 'clean.dist.styles' after 51 ms
[19:44:36] Starting 'styles.dist'...
[19:44:36] 'styles.dist' errored after 244 ms
[19:44:36] TypeError: es.merge is not a function
at Gulp.<anonymous> (/opt/hp/propel/launchpad/node_modules/@propel/gulp-jumpstart-web-packager/gulp/build.js:268:24)
at module.exports (/opt/hp/propel/launchpad/node_modules/orchestrator/lib/runTask.js:34:7)
at Gulp.Orchestrator._runTask (/opt/hp/propel/launchpad/node_modules/orchestrator/index.js:273:3)
at Gulp.Orchestrator._runStep (/opt/hp/propel/launchpad/node_modules/orchestrator/index.js:214:10)
at /opt/hp/propel/launchpad/node_modules/orchestrator/index.js:279:18
at finish (/opt/hp/propel/launchpad/node_modules/orchestrator/lib/runTask.js:21:8)
at cb (/opt/hp/propel/launchpad/node_modules/orchestrator/lib/runTask.js:29:3)
at module.exports (/opt/hp/propel/launchpad/node_modules/each-async/index.js:22:3)
at /opt/hp/propel/launchpad/node_modules/del/index.js:34:3
at /opt/hp/propel/launchpad/node_modules/globby/node_modules/async/lib/async.js:274:13

NOTE: Gulp is a tool that helps you out with several tasks when it comes to web development. It's often used to do front end tasks like:

• Spinning up a web server
• Reloading the browser automatically whenever a file is saved
• Optimizing assets like CSS, JavaScript, and images

es.merge is not recognized by gulp-jumpstart-web-packager. The dependencies of event-stream is 3.2.1 or higher, but unfortunately OOB, the finally installed event-stream bundle version is 0.5.3, and this version did not implement "merge" function yet.

Execute the following command to resolve the problem:
npm install event-stream@3.3.1
Following this ensure that the theming process is executed as per the documentation using the propel account and not the root account.

Defect https://softwaresupport.hp.com/group/softwaresupport/search-result/-/facetsearch/document/KM02911142 has been open to address this issue in a future release of the product.