get_nodes leak ?

create_project -force -part $::env(XRAY_PART) design design
set_property design_mode PinPlanning [current_fileset]
open_io_design -name io_1

set downhill_fp [open downhill_wires.txt w]
set uphill_fp [open uphill_wires.txt w]
set pips_fp [open pips_orig.txt w]
#set_param tcl.collectionResultDisplayLimit 0
set_param messaging.disableStorage 1

set pips [get_pips]

for { set i 0 } { $i < [llength $pips] } { incr i } {
    set dwn_nodes [get_nodes -downhill -of_object [lindex $pips $i]]
    for { set j 0 } { $j < [llength $dwn_nodes] } { incr j } {
        #puts [lindex $dwn_nodes $j]
    }
    unset dwn_nodes
}

close $pips_fp
close $downhill_fp
close $uphill_fp