Ah, fedora upgrades using fedup ...

Starting with Fedora 20, did
  > yum update
and then
  > fedup --network 21 --product=nonproduct
Took a while but there were no issues but
remember, as root
  > export PATH=$PATH:$HOME/bin:/sbin:/usr/sbin
or use
  > su -
to become root otherwise fedup has an issue.

So, now rebooted and it started.
I have all my machines in multi-user mode just
in case there is an issue with X.
Now tried to start X ... and there was an issue.

From bottom of /var/log/Xorg.0.log
[    53.686] (II) Module "dri2" already built-in
[    53.686] (EE) NOUVEAU(0): [drm] failed to set drm interface version.
[    53.686] (EE) NOUVEAU(0): [drm] error opening the drm
[    53.686] (EE) NOUVEAU(0): 892:
[    53.686] (II) UnloadModule: "nouveau"
[    53.686] (EE) Screen(s) found, but none have a usable configuration.
[    53.686] (EE)
Fatal server error:
[    53.686] (EE) no screens found(EE)

START ALL /var/log/Xorg.0.log
[    67.937]
X.Org X Server 1.16.3
Release Date: 2014-12-20
[    67.937] X Protocol Version 11, Revision 0
[    67.937] Build Operating System:  3.17.8-300.bz1178975.fc21.x86_64
[    67.937] Current Operating System: Linux localhost.localdomain 4.0.8-200.fc21.x86_64 #1 SMP Fri Jul 10 21:09:54 UTC 2015 x86_64
[    67.937] Kernel command line: BOOT_IMAGE=/vmlinuz-4.0.8-200.fc21.x86_64 root=/dev/mapper/luks-2a80faec-d21d-4a06-80fe-ad5a445d8aa1 ro rd.luks.uuid=luks-2a80faec-d21d-4a06-80fe-ad5a445d8aa1 vconsole.font=latarcyrheb-sun16 rd.luks.uuid=luks-8597ed23-e47c-427d-834c-e2fc5ec21bd3 rhgb quiet LANG=en_US.UTF-8
[    67.937] Build Date: 31 January 2015  11:23:27PM
[    67.937] Build ID: xorg-x11-server 1.16.3-2.fc21
[    67.937] Current version of pixman: 0.32.6
[    67.937]    Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
[    67.937] Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[    67.937] (==) Log file: "/var/log/Xorg.0.log", Time: Fri Jul 24 21:05:21 2015
[    67.937] (==) Using config directory: "/etc/X11/xorg.conf.d"
[    67.937] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[    67.938] (==) No Layout section.  Using the first Screen section.
[    67.938] (==) No screen section available. Using defaults.
[    67.938] (**) |-->Screen "Default Screen Section" (0)
[    67.938] (**) |   |-->Monitor "<default monitor>"
[    67.938] (==) No monitor specified for screen "Default Screen Section".
        Using a default monitor configuration.
[    67.938] (==) Automatically adding devices
[    67.938] (==) Automatically enabling devices
[    67.938] (==) Automatically adding GPU devices
[    67.938] (==) FontPath set to:
        catalogue:/etc/X11/fontpath.d,
        built-ins
[    67.938] (==) ModulePath set to "/usr/lib64/xorg/modules"
[    67.938] (II) The server relies on udev to provide the list of input devices.
        If no devices become available, reconfigure udev or disable AutoAddDevices.
[    67.938] (II) Loader magic: 0x81de40
[    67.938] (II) Module ABI versions:
[    67.938]    X.Org ANSI C Emulation: 0.4
[    67.938]    X.Org Video Driver: 18.0
[    67.938]    X.Org XInput driver : 21.0
[    67.938]    X.Org Server Extension : 8.0
[    67.943] (II) systemd-logind: took control of session /org/freedesktop/login1/session/_32
[    67.944] (II) xfree86: Adding drm device (/dev/dri/card0)
[    67.944] (II) systemd-logind: got fd for /dev/dri/card0 226:0 fd 10 paused 0
[    67.946] (--) PCI:*(0:6:0:0) 10de:0649:1462:7220 rev 161, Mem @ 0xfd000000/16777216, 0xd0000000/268435456, 0xfa000000/33554432, I/O @ 0x0000ec00/128, BIOS @ 0x????????/524288
[    67.946] (II) LoadModule: "glx"
[    67.946] (II) Loading /usr/lib64/xorg/modules/extensions/libglx.so
[    67.948] (II) Module glx: vendor="X.Org Foundation"
[    67.948]    compiled for 1.16.3, module version = 1.0.0
[    67.948]    ABI class: X.Org Server Extension, version 8.0
[    67.948] (==) AIGLX enabled
[    67.948] (==) Matched nouveau as autoconfigured driver 0
[    67.948] (==) Matched nv as autoconfigured driver 1
[    67.948] (==) Matched nouveau as autoconfigured driver 2
[    67.948] (==) Matched nv as autoconfigured driver 3
[    67.948] (==) Matched modesetting as autoconfigured driver 4
[    67.948] (==) Matched fbdev as autoconfigured driver 5
[    67.948] (==) Matched vesa as autoconfigured driver 6
[    67.948] (==) Assigned the driver to the xf86ConfigLayout
[    67.948] (II) LoadModule: "nouveau"
[    67.991] (II) Loading /usr/lib64/xorg/modules/drivers/nouveau_drv.so
[    67.991] (II) Module nouveau: vendor="X.Org Foundation"
[    67.991]    compiled for 1.16.1, module version = 1.0.11
[    67.991]    Module class: X.Org Video Driver
[    67.991]    ABI class: X.Org Video Driver, version 18.0
[    67.991] (II) LoadModule: "nv"
[    67.991] (WW) Warning, couldn't open module nv
[    67.991] (II) UnloadModule: "nv"
[    67.991] (II) Unloading nv
[    67.991] (EE) Failed to load module "nv" (module does not exist, 0)
[    67.991] (II) LoadModule: "modesetting"
[    67.991] (II) Loading /usr/lib64/xorg/modules/drivers/modesetting_drv.so
[    67.991] (II) Module modesetting: vendor="X.Org Foundation"
[    67.992]    compiled for 1.16.0, module version = 0.9.0
[    67.992]    Module class: X.Org Video Driver
[    67.992]    ABI class: X.Org Video Driver, version 18.0
[    67.992] (II) LoadModule: "fbdev"
[    67.992] (II) Loading /usr/lib64/xorg/modules/drivers/fbdev_drv.so
[    67.992] (II) Module fbdev: vendor="X.Org Foundation"
[    67.992]    compiled for 1.16.0, module version = 0.4.3
[    67.992]    Module class: X.Org Video Driver
[    67.992]    ABI class: X.Org Video Driver, version 18.0
[    67.992] (II) LoadModule: "vesa"
[    67.992] (II) Loading /usr/lib64/xorg/modules/drivers/vesa_drv.so
[    67.992] (II) Module vesa: vendor="X.Org Foundation"
[    67.992]    compiled for 1.16.0, module version = 2.3.2
[    67.992]    Module class: X.Org Video Driver
[    67.992]    ABI class: X.Org Video Driver, version 18.0
[    67.992] (II) NOUVEAU driver
[    67.992] (II) NOUVEAU driver for NVIDIA chipset families :
[    67.992]    RIVA TNT        (NV04)
[    67.992]    RIVA TNT2       (NV05)
[    67.992]    GeForce 256     (NV10)
[    67.992]    GeForce 2       (NV11, NV15)
[    67.992]    GeForce 4MX     (NV17, NV18)
[    67.992]    GeForce 3       (NV20)
[    67.992]    GeForce 4Ti     (NV25, NV28)
[    67.992]    GeForce FX      (NV3x)
[    67.992]    GeForce 6       (NV4x)
[    67.992]    GeForce 7       (G7x)
[    67.992]    GeForce 8       (G8x)
[    67.992]    GeForce GTX 200 (NVA0)
[    67.992]    GeForce GTX 400 (NVC0)
[    67.992] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[    67.992] (II) FBDEV: driver for framebuffer: fbdev
[    67.992] (II) VESA: driver for VESA chipsets: vesa
[    67.992] (--) using VT number 2

[    68.007] (II) [drm] nouveau interface version: 1.2.1
[    68.007] (WW) Falling back to old probe method for modesetting
[    68.007] (WW) Falling back to old probe method for fbdev
[    68.007] (II) Loading sub module "fbdevhw"
[    68.007] (II) LoadModule: "fbdevhw"
[    68.007] (II) Loading /usr/lib64/xorg/modules/libfbdevhw.so
[    68.007] (II) Module fbdevhw: vendor="X.Org Foundation"
[    68.007]    compiled for 1.16.3, module version = 0.0.2
[    68.007]    ABI class: X.Org Video Driver, version 18.0
[    68.007] (WW) Falling back to old probe method for vesa
[    68.007] (II) Loading sub module "dri2"
[    68.007] (II) LoadModule: "dri2"
[    68.007] (II) Module "dri2" already built-in
[    68.007] (EE) NOUVEAU(0): [drm] failed to set drm interface version.
[    68.007] (EE) NOUVEAU(0): [drm] error opening the drm
[    68.007] (EE) NOUVEAU(0): 892:
[    68.008] (II) UnloadModule: "nouveau"
[    68.008] (EE) Screen(s) found, but none have a usable configuration.
[    68.008] (EE)
Fatal server error:
[    68.008] (EE) no screens found(EE)
[    68.008] (EE)
Please consult the Fedora Project support
         at http://wiki.x.org
 for help.
[    68.008] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[    68.008] (EE)
[    68.041] (EE) Server terminated with error (1). Closing log file.

END ALL /var/log/Xorg.0.log

START dmesg
dmesg | grep nouv
[    1.620030] nouveau  [  DEVICE][0000:06:00.0] BOOT0  : 0x096480a1
[    1.620033] nouveau  [  DEVICE][0000:06:00.0] Chipset: G96 (NV96)
[    1.620035] nouveau  [  DEVICE][0000:06:00.0] Family : NV50
[    1.754789] nouveau  [   VBIOS][0000:06:00.0] using image from PRAMIN
[    1.754906] nouveau  [   VBIOS][0000:06:00.0] BIT signature found
[    1.754909] nouveau  [   VBIOS][0000:06:00.0] version 62.94.3c.00.22
[    1.775559] nouveau  [     MXM][0000:06:00.0] BIOS version 2.1
[    1.777641] nouveau  [     MXM][0000:06:00.0] MXMS Version 2.1
[    1.777689] nouveau  [     PMC][0000:06:00.0] MSI interrupts enabled
[    1.777726] nouveau  [     PFB][0000:06:00.0] RAM type: GDDR3
[    1.777728] nouveau  [     PFB][0000:06:00.0] RAM size: 512 MiB
[    1.777730] nouveau  [     PFB][0000:06:00.0]    ZCOMP: 2048 tags
[    1.779195] nouveau  [    VOLT][0000:06:00.0] GPU voltage: 890000uv
[    1.807654] nouveau  [  PTHERM][0000:06:00.0] FAN control: none / external
[    1.807671] nouveau  [  PTHERM][0000:06:00.0] fan management: automatic
[    1.807677] nouveau  [  PTHERM][0000:06:00.0] internal sensor: yes
[    1.827743] nouveau  [     CLK][0000:06:00.0] 03: core 169 MHz shader 338 MHz memory 100 MHz
[    1.827747] nouveau  [     CLK][0000:06:00.0] 05: core 275 MHz shader 550 MHz memory 300 MHz
[    1.827751] nouveau  [     CLK][0000:06:00.0] 07: core 400 MHz shader 800 MHz memory 300 MHz
[    1.827754] nouveau  [     CLK][0000:06:00.0] 0f: core 500 MHz shader 1250 MHz memory 800 MHz
[    1.827833] nouveau  [     CLK][0000:06:00.0] --: core 275 MHz shader 550 MHz memory 300 MHz
[    1.831172] nouveau  [     DRM] VRAM: 512 MiB
[    1.831174] nouveau  [     DRM] GART: 1048576 MiB
[    1.831179] nouveau  [     DRM] TMDS table version 2.0
[    1.831181] nouveau  [     DRM] DCB version 4.0
[    1.831183] nouveau  [     DRM] DCB outp 00: 01000323 00010034
[    1.831185] nouveau  [     DRM] DCB outp 02: 04011312 00020010
[    1.831187] nouveau  [     DRM] DCB outp 06: 02044300 00000028
[    1.831189] nouveau  [     DRM] DCB conn 00: 00000040
[    1.831192] nouveau  [     DRM] DCB conn 01: 00001131
[    1.831193] nouveau  [     DRM] DCB conn 02: 00002231
[    1.831195] nouveau  [     DRM] DCB conn 03: 00110346
[    1.831197] nouveau  [     DRM] DCB conn 04: 00000400
[    1.831199] nouveau  [     DRM] DCB conn 05: 00000510
[    1.831200] nouveau  [     DRM] DCB conn 06: 00000511
[    1.831202] nouveau  [     DRM] DCB conn 07: 00000513
[    1.831204] nouveau  [     DRM] DCB conn 08: 00002631
[    1.831205] nouveau  [     DRM] DCB conn 09: 00001731
[    1.831207] nouveau  [     DRM] DCB conn 10: 00002831
[    1.831209] nouveau  [     DRM] DCB conn 11: 00110946
[    1.831210] nouveau  [     DRM] DCB conn 12: 00000a00
[    1.831212] nouveau  [     DRM] DCB conn 13: 00000b10
[    1.831214] nouveau  [     DRM] DCB conn 14: 00000b11
[    1.831215] nouveau  [     DRM] DCB conn 15: 00000b13
[    1.859852] nouveau  [     DRM] MM: using CRYPT for buffer copies
[    2.969414] nouveau  [     DRM] allocated 1680x1050 fb: 0x70000, bo ffff88003640a400
[    2.969504] fbcon: nouveaufb (fb0) is primary device
[    3.284089] nouveau 0000:06:00.0: fb0: nouveaufb frame buffer device
[    3.284091] nouveau 0000:06:00.0: registered panic notifier
[    3.290053] [drm] Initialized nouveau 1.2.1 20120801 for 0000:06:00.0 on minor 0
END dmesg

So, fedup somehow blew away something.
The Question is what?

rpm -qa --qf '%{NAME} %{VERSION}-%{RELEASE} %{ARCH}\n' | grep kmod
kmod-libs 19-1.fc21 x86_64
kmod 19-1.fc21 x86_64

What did fedup change and how can I recover?

Thanks
Richard