/usr/share/nrn/lib/hoc/chanbild/ is in neuron 7.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/nrn/lib/hoc/chanbild/chanbild1.hoc
/usr/share/nrn/lib/hoc/chanbild/const.hoc
/usr/share/nrn/lib/hoc/chanbild/exp.hoc
/usr/share/nrn/lib/hoc/chanbild/gategui.hoc
/usr/share/nrn/lib/hoc/chanbild/kschanbg.hoc
/usr/share/nrn/lib/hoc/chanbild/ksgate.hoc
/usr/share/nrn/lib/hoc/chanbild/ksstate.hoc
/usr/share/nrn/lib/hoc/chanbild/kstgui.hoc
/usr/share/nrn/lib/hoc/chanbild/kstrans.hoc
/usr/share/nrn/lib/hoc/chanbild/linoid.hoc
/usr/share/nrn/lib/hoc/chanbild/properties.hoc
/usr/share/nrn/lib/hoc/chanbild/sigmoid.hoc
/usr/share/nrn/lib/hoc/chanbild/table.hoc