As a matter of fact, changing lines 37-38 of /usr/games/scid from
package require Tk 8.5 if {$tcl_version == 8.5} { catch {package require img::png} } to # package require Tk 8.5 if {$tcl_version == 8.6} { catch {package require img::png} } seems necessary but is sufficient to have scid running. Whether the issue is scid or tcl or tk related remains mysterious to me. Best, -- fm