Pakistan Railways has started work on a project to lay an 11 km railway line from Chaman to Spin Boldak in Afghanistan, SAMAA TV reported on 5 November 2021. “The construction material is being transported to the area to lay the track which will extend to the zero line, SAMAA TV‘s Saeed Achakzai reported on Friday. Pakistan Railways officials told SAMAA TV that the rails would soon be laid on the sleepers. The most recent effort to construct the Chaman-Spin Boldak line was launched last December when Railways Minister Sheikh Rasheed Ahmed announced the revival of the project.”

There is also some history, citing this website :-)