[Interest] Debugging in Qt Creator and displaying Qt objects d_ptr members in watch window ?

Michael Jackson imikejackson at gmail.com
Thu Sep 17 18:07:58 CEST 2015

On Sep 17, 2015, at 11:50 AM, John Weeks <john at wavemetrics.com> wrote:

> We use our own build of Qt 5.5, including a debug build. Debugging is often painfully slow but mostly works. And with a debug build of Qt we can step into Qt code and (usually) inspect d pointers.
> Be sure that you have gone into the Projects tab in Qt Creator, select the Run half of the button for the kit you're using and turn on the checkbox "Use debug version of frameworks"
> <PastedGraphic-1.png>
> Who else thinks that black Build button looks selected? But it's not- the Run button is active!
> -John Weeks
> WaveMetrics, Inc.

I had not thought about trying the debug versions of the frameworks but I don't think (for us) it is the issue. We can not even debug our _own_ codes, let alone anything from Qt, but maybe the debug versions have something to do with it? Worth a try. Of course trying to build Qt isn't as easy as it used to be back in the 4.x days. We depend on QtWebEngine so there is all of that. And our packaging system depends on an installation from Digia, not a home built installation. I'll have to setup a couple of different sandboxes. One with our build and one with the official Digia builds.

<starting opinion>Not that I expect this to help at all. The LLDB integration is just plain is buggy. I'll assume none of the pertinent developers at Digia actually use LLDB to debug. I bet they all use GDB because the LLDB integration sucks. Such an evil circle to be in. Clearly no "dog fooding" going on.</starting opinion>

And yes, the nightly builds of QtCreator are buggy. There is a crasher in the Clang code model where it tries to supply the editor with a completion hint but crashes instead. And then the editor just gets slower and slower as you type. I found a build from Sept 10 that _mostly_ works, at least the editing mostly works. Only crashes a few times an hour. Just remember to "save often".

Mike Jackson

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