[Discuss-gnuradio] variable @FSM_FILE_INSTALL_DIR@ does not evaluate in grc

From the latest master, when I run one of the examples in gr-trellis/examples/grc,
the value of the parameter "prefix" which is set to @FSM_FILE_INSTALL_DIR@

does not evaluate...

Can someone confirm?

Is there something I should do to set it?

thanks
Achilleas