I have installed SystemWorkbench imported my CubeMX generate project and everything works fine.
Now I want to port some Linux code. Therefore I added those files to the project and build to see the errors. When I compiled to see the errors, to my suprice the Linux POSIX header like pthread.h are found in the fr.ac6.mcu.externaltools.arm-none.win32_220.127.116.11812190825 directory (so only linker errors).
But I cannot imagine that there is a library for the STM32F4 which implements the e.g. pthread.
Why are those POSIX headers there (and found when compiling) what is the purpose?