Your question sent me off trying to figure that out, thank you.

When I first added poppler (the qt5 bindings) I tried to use qtcreator to locate them, and I used Add Library, and External Library to locate them as that seemed most applicable. That works, but it adds a ton of conditionals and an explicit path to the library itself which included /usr/lib/x86_64-linux-gnu/.

Seeing the conditionals made me think I was supposed to find one matching the Pi and change it there, but after your question I dug a bit more and realized I should find the library with the native OS (just list it in LIBS by name) and for the include I could either put it in the INCLUDEPATH or start with the top level and do #include "poppler/qt5/poppler-qt5.h". I'm not sure which is most correct, but neither of them appear to cause errors in porting to the other platform.

So I no longer have a path I need to change in the project file, works nicely. Thanks for the shove.

Part of the reason for the original question was a sense from some postings (here's one) that one shouldn't move project files, but maybe I read to much into that. And if moving a project file is OK, then I really do not think I care whether someone who gets this builds it on the pi, or cross compiles, in which case...

I think the answer to the original question is: It doesn't matter. Right?