Qt build path issue and file not found

There are two projects, FFObject and DDS, corresponding to two. pro files. After the DDS project is built, a libDDS. a file will be generated, which is required for the FFObject project during construction. But no matter how I modify the build path, I always get an error saying that I can't find the libDDS. a file when building FFObjects. The following is the code for finding files in the FFObject. pro file, the path for building DDS, and error messages. May I ask how to handle this situation. DDS Build Path:enter image description here The code in the FFObject. pro file:enter image description here Error message:enter image description here

These two projects are not in the same project file, they are separate projects

I tried to modify the build directory many times, but none of them had any effect.

In your .pro file you have win32: ... LIBS += -L$$OUT_PWD/../DDS/release -lDDS. But in your first image it shows the build path to be in a folder named "build-FFObject-Desktop...". So, I suspect the path added to LIBS is not valid.

Here is what I would suggest you to try:

1. Disable "Shadow build" in your Qt Creator Project mode build settings for both projects to get more predictable build paths:

Maybe after unchecking the Shadow build the directory structure would be more in line what you expect it to be. The shadow build option is what creates that separate "build-FFObject-Desktop..." build directory. Without it the library will be built next to the source code.

2. If it still does not work, add a message command to your .pro file to actually print out where does it look for the files and then make sure the file exists there. Something like message("-L$$OUT_PWD/../DDS/release/libDDS.a"). After adding the message, run qmake and check the "Compile Output" pane to see the printout of a path where the .a file is supposed to be.