use gcc toolchain and use another alternative linker.

[fasxmut]

Looks like b2 can not use an alternative linker for gcc. I want it because I want to use latest c++23 support implemented by gcc and sycl together. This link shows I can compile c++ code with gcc, and link the code with dpcpp as linker:
https://stackoverflow.com/questions/68158506/create-a-static-or-shared-library-from-sycl-program-using-dpc
It works fine by hand commands, but how to do it in b2 build jamfile?

[grafikrobot]

You can add this to your user-config.jam:

toolset.flags gcc.link CONFIG_COMMAND <toolset>gcc : dpcpp : unchecked ;

You will need to make sure to either have dpcpp in the PATH. Or specify the full path to it. If you are using multiple versions of gcc you can also specify the equivalent of <toolset>gcc-13 (i.e. with the version) instead of the catch all. And if you also need to link shared libs with dpcpp you can add another flags declaration with gcc.link.dll.