Bug 210177

Created attachment 395782 [details] Running Keyboard Maestro's custom Window with its Web Inspector during debugging. Hi, I have updated catalina to recent release 10.15.4 and Xcode to Xcode Version 11.4 (11E146), and have installed the component required by Xcode. I using a commercial application called Keyboard Maestro ( www.keyboardmaestro.com/) and it has a feature that use webkit call Custom HTML Prompt Action (https://wiki.keyboardmaestro.com/action/Custom_HTML_Prompt) whereby one can use a html file to show in a window. It is able to access web inspector as shown in file attachment. Before update to 10.15.4, the debugger in the web inspector use to work if there is breakpoint, however after update to 10.15.4 and xcode, the debugger hang (a snowball icon show) whenever it stop at breakpoint. All function of web inspector is working except debugger operation. It seems that something is broken understanding that from https://webkit.org/blog/10247/new-webkit-features-in-safari-13-1/ , webkit get update which may possibly break thing. I have no idea what is happening as there are commerical application that using webkit and breaking such thing is disappointing especially this is used for business. I have attached the image , whereby Test Custom Prompt window is the window created by Keyboard Maestro using its "Custom HTML Prompt Action ", and web inspector is shown, and when button click and stop at breakpoint, the mouse cursor turn snowball , and hang the whole Keyboard Maestro, seem like web inspector's debugger is having issue ? Can you investigate and fix this issue ? I am okay with accessing my macbook remotely for troubleshooting and debugging this issue. thank