# qt 5.15 - how to deploy the qt debug dlls

• Hi,

long time qt user here.
I am using qt online installer, on windows, 64 bit, mingw build.

Until recently, we used qt 5.12, which comes with two sets of dlls, one for debug, one for release
e.g. Qt5Core.dll (release build) and Qt5Cored.dll (debug build - note the d at the end).

Having upgraded to 5.15 (and I tried 5.14 as well) I get the following problem
my debug build links against Qt5Core.dll (no d at the end).

which is weird, I was expecting Qt5Cored.dll (with a d at the end).
Well

• either qt company has changed the way they name the dlls (no longer use the d at the end for their debug dlls)
• or, this is a bug, somewhere in the (qmake generated) build scripts (they should still use Qt5Cored but for some reason they don't)

I try to deploy the qt dlls next to my module and debug my module

1. I noticed that it detecs my binary as a "release" build

and it is NOT a release, I checked with objdump, debug sections are there

so...

1. I tried to override by adding --debug in the command line
``````windeployqt --debug mymodule.exe
``````

and I get nothing but the release qt dlls next to my module.exe (Qt5Core.dll, Qt5Gui.dll, plugins...)

which, of course is not debuggable (I launch the debugger, and it just stops)

where are the symbol files? how do I get the debug qt binaries in order to debug everything?

Thanks a lot

• There are no debug dlls for MinGW anymore.
The binaries from the installer are created with -release -force-debug-info -separate-debug-info.
So the symbol files are generated separately.
You should be able to find them (*.dll.debug) in the lib folder if you've chosen to install with the debug information files.

• There are no debug dlls for MinGW anymore.
The binaries from the installer are created with -release -force-debug-info -separate-debug-info.
So the symbol files are generated separately.
You should be able to find them (*.dll.debug) in the lib folder if you've chosen to install with the debug information files.