Cannot disable ES5 transpilations

Moved from here: https://github.com/vaadin/framework/issues/11504

• Vaadin Framework version: 13.0.1
• Browser version: Google Chrome Version 72.0.3626.121 (Official Build) (64-bit)

If I disable the ES5 transpile in the maven build, with <skipEs5>true</skipEs5>, I still get the following exception, even with latest Chrome and also Safari:

java.lang.IllegalArgumentException: Failed to find the bundle manifest file ‘frontend://vaadin-flow-bundle-manifest.json’ in the servlet context for ‘ES5’ browsers. If you are running a dev-mode servlet container in maven e.g. jetty:run change it to jetty:run-exploded. If you are not compiling frontend resources, include the ‘vaadin-maven-plugin’ in your build script. Otherwise, you can skip this error either by disabling production mode, or by setting the servlet parameter ‘original.frontend.resources=true’. Vaadin plugin is obsviouly enabled, just skipping ES5, but this error happens anyway. ES5 support is pretty useless for me, so I would like to avoid having to compile it.

Can you fix this bug, please?

[jm-ferreira]

Starting from Vaadin 14.2 ES5 transpilation is disabled by default while running in DevMode.

[gsedlacz]

The issue is remains present in 14.0.0.beta3. As this is an officially documented feature a bugfix would be nice.

Thank you.