Boxes just displays "Failed to start 'Foo'"

$ gnome-boxes

(gnome-boxes:28712): GLib-GObject-WARNING **: The property GtkCellRendererPixbuf:follow-state is deprecated and shouldn't be used anymore. It will be removed in a future version.

(gnome-boxes:28712): Boxes-WARNING **: machine.vala:594: Failed to start Fedora 20: Unable to start domain: failed to retrieve file descriptor for interface: Transport endpoint is not connected

Troubleshooting Log:

Broker URL: qemu+unix:///session
Domain: fedora20
UUID: 13746b2a-f755-4cd4-8901-f52df45ec61f
Persistent: yes
Cpu time: 0
Memory: 0 KiB
Max memory: 16358052 KiB
CPUs: 12
State: GVIR_DOMAIN_STATE_SHUTOFF

Domain config:
------------------------------------------------------------
<domain type="kvm">
  <name>fedora20</name>
  <uuid>13746b2a-f755-4cd4-8901-f52df45ec61f</uuid>
  <title>Fedora 20</title>
  <metadata>
    <boxes:gnome-boxes xmlns:boxes="http://live.gnome.org/Boxes/">
      <os-state>installed</os-state>
      <os-id>http://fedoraproject.org/fedora/20</os-id>
      <media-id>http://fedoraproject.org/fedora/20:3</media-id>
      <media>/home/jimmac/Downloads/Fedora-Live-Desktop-x86_64-20-1.iso</media>
    </boxes:gnome-boxes>
  </metadata>
  <memory unit="KiB">1048576</memory>
  <currentMemory unit="KiB">1048576</currentMemory>
  <vcpu placement="static">12</vcpu>
  <os>
    <type arch="x86_64" machine="pc-i440fx-2.1">hvm</type>
    <boot dev="hd"/>
  </os>
  <features>
    <acpi/>
    <apic/>
  </features>
  <cpu mode="custom" match="exact">
    <model fallback="allow">SandyBridge</model>
    <topology sockets="1" cores="6" threads="2"/>
  </cpu>
  <clock offset="utc">
    <timer name="rtc" tickpolicy="catchup"/>
    <timer name="pit" tickpolicy="delay"/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <pm>
    <suspend-to-mem enabled="no"/>
    <suspend-to-disk enabled="no"/>
  </pm>
  <devices>
    <emulator>/usr/bin/qemu-kvm</emulator>
    <disk type="file" device="disk">
      <driver name="qemu" type="qcow2" cache="none"/>
      <source file="/home/jimmac/.local/share/gnome-boxes/images/fedora20"/>
      <target dev="vda" bus="virtio"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x07" function="0x0"/>
    </disk>
    <disk type="file" device="cdrom">
      <driver name="qemu" type="raw"/>
      <source file="/home/jimmac/Downloads/Fedora-Live-Desktop-x86_64-20-1.iso" startupPolicy="optional"/>
      <target dev="hdc" bus="ide"/>
      <readonly/>
      <address type="drive" controller="0" bus="1" target="0" unit="0"/>
    </disk>
    <controller type="usb" index="0" model="ich9-ehci1">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x7"/>
    </controller>
    <controller type="usb" index="0" model="ich9-uhci1">
      <master startport="0"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x0" multifunction="on"/>
    </controller>
    <controller type="usb" index="0" model="ich9-uhci2">
      <master startport="2"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x1"/>
    </controller>
    <controller type="usb" index="0" model="ich9-uhci3">
      <master startport="4"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x05" function="0x2"/>
    </controller>
    <controller type="pci" index="0" model="pci-root"/>
    <controller type="ide" index="0">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x01" function="0x1"/>
    </controller>
    <controller type="virtio-serial" index="0">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x06" function="0x0"/>
    </controller>
    <controller type="ccid" index="0"/>
    <interface type="bridge">
      <mac address="52:54:00:b4:68:d3"/>
      <source bridge="virbr0"/>
      <target dev="tap2"/>
      <model type="virtio"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0"/>
    </interface>
    <smartcard mode="passthrough" type="spicevmc">
      <address type="ccid" controller="0" slot="0"/>
    </smartcard>
    <serial type="pty">
      <target port="0"/>
    </serial>
    <console type="pty">
      <target type="serial" port="0"/>
    </console>
    <channel type="spicevmc">
      <target type="virtio" name="com.redhat.spice.0"/>
      <address type="virtio-serial" controller="0" bus="0" port="1"/>
    </channel>
    <input type="tablet" bus="usb"/>
    <input type="mouse" bus="ps2"/>
    <input type="keyboard" bus="ps2"/>
    <graphics type="spice" autoport="yes" listen="127.0.0.1">
      <listen type="address" address="127.0.0.1"/>
      <image compression="off"/>
    </graphics>
    <sound model="ac97">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x04" function="0x0"/>
    </sound>
    <video>
      <model type="qxl" ram="65536" vram="65536" vgamem="16384" heads="1"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x0"/>
    </video>
    <redirdev bus="usb" type="spicevmc">
    </redirdev>
    <redirdev bus="usb" type="spicevmc">
    </redirdev>
    <redirdev bus="usb" type="spicevmc">
    </redirdev>
    <redirdev bus="usb" type="spicevmc">
    </redirdev>
    <memballoon model="virtio">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x08" function="0x0"/>
    </memballoon>
  </devices>
</domain>
------------------------------------------------------------

QEMU log:
------------------------------------------------------------
2015-08-25 20:11:14.754+0000: shutting down
------------------------------------------------------------