tomahawk-player/tomahawk — comment on commit 0d9e248dacc0989b6a3a142dbc04a07338cc3c10
File:  line 0
By dschmidt:

...because the old macro used __attribute__ ((visibility ("default"))) which is the same for exporting and importing. Now with Q_DECL_EXPORT (__declspec(dllexport)) // Q_DECL_IMPORT (__declspec(dllimport)) importing/exporting is different.. the conclusion: it could never work in MSVC