when setting guioptions: Invalid argument

[holomorph]

With `firefox -pentadactyl '+u NONE'

Pentadactyl 1.2pre (created 2015/06/13 18:10:28) running on:
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Firefox/38.0

I do :set guioptions-=r and get

Invalid argument: guioptions-=r: this is undefined

pentadactyl's output:

pentadactyl: Load: abbreviations
pentadactyl:   from: resource://dactyl-content/editor.js:532
pentadactyl: TypeError: this is undefined
pentadactyl: TypeError: this is undefined::
pentadactyl: stack:     stringlist/<@resource://dactyl/options.jsm:711:28
pentadactyl:    stringlist@resource://dactyl/options.jsm:710:1
pentadactyl:    op@resource://dactyl/options.jsm:252:29
pentadactyl:    setAction@resource://dactyl/options.jsm:1248:35
pentadactyl:    initCommands/</<@resource://dactyl/options.jsm:1435:21
pentadactyl:    exec@resource://dactyl/commands.jsm:191:17
pentadactyl:    trapErrors@resource://dactyl-content/dactyl.js:1139:20
pentadactyl:    execute@resource://dactyl/commands.jsm:180:1
pentadactyl:    execute@resource://dactyl-content/dactyl.js:552:26
pentadactyl:    _onSubmit@resource://dactyl-content/commandline.js:480:17
pentadactyl:    withSavedValues@resource://dactyl/base.jsm:1057:20
pentadactyl:    _onSubmit@resource://dactyl-content/commandline.js:477:13
pentadactyl:    withContext/<@resource://dactyl/contexts.jsm:596:20
pentadactyl:    withSavedValues@resource://dactyl/base.jsm:1057:20
pentadactyl:    withContext@resource://dactyl/contexts.jsm:594:9
pentadactyl:    CEM_onSubmit@resource://dactyl-content/commandline.js:475:1
pentadactyl:    CM_leave/<@resource://dactyl-content/commandline.js:409:21
pentadactyl:    trapErrors@resource://dactyl-content/dactyl.js:1139:20
pentadactyl:    set/<@resource://dactyl-content/modes.js:372:13
pentadactyl:    set@resource://dactyl-content/modes.js:371:9
pentadactyl:    pop@resource://dactyl-content/modes.js:396:1
pentadactyl:    initMappings/</<@resource://dactyl-content/commandline.js:1810:33
pentadactyl:    trapErrors@resource://dactyl-content/dactyl.js:1139:20
pentadactyl:    execute@resource://dactyl-content/key-processors.js:89:30
pentadactyl:    process@resource://dactyl-content/key-processors.js:219:16
pentadactyl:    onKeyPress@resource://dactyl-content/events.js:773:22
pentadactyl:    wrappedListener@resource://dactyl-content/events.js:225:17
pentadactyl: toString: function () /* use strict */ String(error)

There's a whole mess of output from firefox after pentadactyl's loading messages, not sure if related. Will pastebin if needed.

[holomorph]

Thank you o/