LNK2001 _DLLMAINCRTStartup problem

[tungyen]

Hello, I am a user of qt6 recently. However, I encountered the problem shown below:

I want to make a package called RCL which contains lib files, DLL files, and an exe file. However, when I run qmake->rebuild, the errors below showed, and I felt quite confused.
The Toolkit. lib is a file that I made previously. And it was strange that when I put boost, armadillo, and the opencascade lib in that project, it work and build successfully. This RCL project built based on Armadillo and Boost fails.
Could someone help me solve this problem? I guess it might not the problem of 3rd party lib

Here is my .pro file: