Hello,
My app builds well with Build Version 2018.3288 for Html.
With Versions 2018.3289 and 2018.3290 I am getting Build Failed Error Code 12 when I build for Html Beta.
=== error log : ===
HTML5 builder started
Failed to clear tmp folder: /var/folders/ls/k0xgm9gj1xb2syzvg0ggm_lr0000gn/T/CLtmpWdeR7J/webapp
ERROR: Build Failed: Error code: 12
======