How do I build a debug mode QT app that links to a lib built in release mode?

[Joachie]

you can built Qt with -debug-and-release configure key, that allows to use Qt in debug and release modes by adding CONFIG += release/debug flag in pro-file of your application.
so, you need:

configure.exe -debug-and-release
mingw32-make (or nmake for MS VC)

configure.exe -debug-and-release
mingw32-make (or nmake for MS VC)

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Thanks, I'll give that a try. Is there a way to do a clean before re-making or re-configing?

[spirit]

yup

mingw32-make clean (or for MS VS: nmake clean)

but you should run this command in QTDIR.

[Joachie]

yup

but you should run this command in QTDIR.

Thanks, QTDIR meaning c:\qt\2009.1\qt in my case?

or the root, being c:\qt\2009.1 ?

[spirit]

QTDIR meaning c:\qt\2009.1\qt in my case?

yes, c:\qt\2009.1\qt.