id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
871	'Session' object has no attribute 'add'	Eric Pettersen	Conrad Huang	"The following commands produce an undo-related traceback:

open 1gcn
sel N
sel C

Traceback (most recent call last):
File ""/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/cmd_line/tool.py"", line 188, in execute
cmd.run(cmd_text)
File ""/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/cli.py"", line 2499, in run
result = ci.function(session, **kw_args)
File ""/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/select.py"", line 36, in select
clear_selection(session, ""select_clear"", undo_state)
File ""/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/select.py"", line 153, in clear_selection
session.selection.undo_add_selected(session, undo_state, False)
File ""/Users/chimera/Applications/ChimeraX_Daily.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/selection.py"", line 79, in undo_add_selected
undo_state.add(a, ""selected"", orig, new_state)
AttributeError: 'Session' object has no attribute 'add'"	defect	closed	blocker	Alpha 4	Undo/Redo		fixed						all	ChimeraX