javagwtgoogle-chrome-devtoolsuibinder

Super Dev Mode pauses on “invisible” breakpoints & then shows blank screen

I’m running GWT Super Dev Mode via ant devmode (with my main server already up in another terminal). The code server launches fine, and I click my “Dev Mode On” bookmarklet in Chrome. Compilation proceeds without errors, but then DevTools immediately pops up saying “Debugger paused.” I didn’t set any breakpoints.

Steps I've already taken:

Disabled all breakpoints in Chrome DevTools (Sources ➤ 🔴 Deactivate Breakpoints).

Cleared any marker breakpoints in my code editor.

Toggled Dev Mode off and back on again—but now I just see a blank screen.

Logs from the terminal during this process:


[java] GET /sourcemaps/ode/D4A92ECC870BD56410DE88EB04617475_sourcemap.json
[java] sent source map for module 'ode' in 169 ms
[java] GET /recompile/ode
[java] Job com.google.appinventor.YaClient-dev_1_2
[java] starting job: com.google.appinventor.YaClient-dev_1_2
[java] binding: locale=en
[java] binding: user.agent=safari
[java] skipped compile because no input files have changed
[java] 0.108s total -- Compile completed
[java] GET /sourcemaps/ode
[java] [WARN] ignored get request: /sourcemaps/ode
[java] [WARN] not handled: /sourcemaps/ode

enter image description here Any guidance or troubleshooting steps would be hugely appreciated!

Solution

  • In super dev mode, asserts compile out to breakpoints - if they fail. Your assertion is failing, and just before it throws, it pauses so you can see what else is going on.

    In this case, a @UiField-decorated field was marked as provided=true, which means it was supposed to be initialized before createAndBind is called, but for some reason it was not. This may break the UI, so UiBinder fails early in dev mode to inform you of this.