とりあえず、pkgIndex.tclのpackage文をコメントアウトすることでバグを回避しました。

#package ifneeded Metawidget 1.2 " source [file join [set dir] metawidget.tcl] #" #package ifneeded mkWidgets 1.2 " source [file join [set dir] Tooltip.tcl] source [file join [set dir] Calendar.tcl] source [file join [set dir] Aclock.tcl] source [file join [set dir] Combobox.tcl] source [file join [set dir] Scrollbox.tcl] source [file join [set dir] Toolbar.tcl] source [file join [set dir] Statusbar.tcl] source [file join [set dir] Textframe.tcl] source [file join [set dir] Window.tcl] source [file join [set dir] Document.tcl] source [file join [set dir] Pane.tcl] source [file join [set dir] Tabcontrol.tcl] source [file join [set dir] Progressbar.tcl] source [file join [set dir] Gridcontrol.tcl] source [file join [set dir] Listcontrol.tcl] source [file join [set dir] Iconbox.tcl] source [file join [set dir] Treecontrol.tcl] source [file join [set dir] Ibutton.tcl] source [file join [set dir] Spinentry.tcl] package provide mkWidgets 1.2 #"