Sorry but I'm not sure I understand your problem : your project looks fine to me and it is definitely the only way to get proper linking if you want to build your project in both debug and release mode.

Are you saying that despite setting up your porject like that you get binaries that always link against the same version of Qwt, regardless of the build?

If so I only have two suggestions :

  • specify proper TARGET and/or DESTDIR for the targets depending on the build mode (i.e inside the CONFIG() blocks)
  • replace
    Qt Code: 
    1. CONFIG(debug,debug|release) {
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    with
    Qt Code: 
    1. CONFIG(debug,release|debug) {
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    . I really don't think it *should* change anything but that's what I'm using in my own projects and things work as expected