This unmaintained abandonware is the latest version of the old forward annotation tool from gschem (or letpon-eda) to pcb-rnd. It is obsolete and largely unmaintained.
Please consider switching to the tEDAx netlist format: both gschem and lepton-eda supports it for years already.
Instead of depending on gsch2pcb-rnd, use pcb-rnd's import sch functionality, either from the GUI or from the command line (e.g. Makefile).
For more info, please read my post to the pcb-rnd mailing list about gsch2pcb-rnd removal from pcb-rnd.
If you still insist on using this dead software, you can get it from: