setxkbmap -I /usr/local/share/X11/xkb broken

x11-xkb-utils 7.7+1 (as supplied with Ubuntu 14.04 - Trusty)

setxkbmap -I /usr/local/share/X11/xkb should search first in /usr/local/share/X11/xkb, and if not found then search in /usr/share/X11/xkb
Instead, it appears to search first in the current directory, and then in /usr/share/X11/xkb

To reproduce, set up some file in /usr/local/share/X11/xkb/rules. For example, I created a modified version of evdev with
$ diff /usr/share/X11/xkb/rules/evdev /usr/local/share/X11/xkb/rules/evdev
247c247,248
< * $sun_custom $sun_var = pc+sun_vndr/%l%(v)
---
> ! * $sun_custom $sun_var = pc+sun_vndr/%l%(v)
> $sun gb mod3 = pc+gb(mod3)
332c333,334
< $sun $sun_custom = pc+sun_vndr/%l%(v)
---
> ! $sun $sun_custom = pc+sun_vndr/%l%(v)
> $sun gb pc+gb%(v)

Then
$ cd /usr/local/share/X11/xkb/
$ setxkbmap -query -v 10 -model sun_type6_unix_usb -layout gb -variant mod3
Setting verbose level to 10
locale is C
Warning! Multiple definitions of keyboard model
         Using command line, ignoring X server
Warning! Multiple definitions of keyboard layout
         Using command line, ignoring X server
Warning! Multiple definitions of layout variant
         Using command line, ignoring X server
Trying to load rules file ./rules/evdev...
Success.
Applied rules from evdev:
rules: evdev
model: sun_type6_unix_usb
layout: gb
variant: mod3
Trying to build keymap using the following components:
keycodes: evdev+aliases(qwerty)
types: complete
compat: complete
symbols: pc+gb(mod3)+inet(evdev)
geometry: sun(type6unix)
rules: evdev
model: sun_type6_unix_usb
layout: gb
variant: mod3

Observe the "symbols: pc+gb(mod3)+inet(evdev)" which is exactly what I wanted (clearly I had also to set up a suitably hacked symbols/gb file)

Now try the following from the home directory, which ought to have produced the same result:

$ cd
$ setxkbmap -I /usr/local/share/X11/xkb -query -v 10 -model sun_type6_unix_usb -layout gb -variant mod3
Setting verbose level to 10
locale is C
Warning! Multiple definitions of keyboard model
         Using command line, ignoring X server
Warning! Multiple definitions of keyboard layout
         Using command line, ignoring X server
Warning! Multiple definitions of layout variant
         Using command line, ignoring X server
Trying to load rules file ./rules/evdev...
Trying to load rules file /usr/share/X11/xkb/rules/evdev...
Success.
Applied rules from evdev:
rules: evdev
model: sun_type6_unix_usb
layout: gb
variant: mod3
Trying to build keymap using the following components:
keycodes: evdev+aliases(qwerty)
types: complete
compat: complete
symbols: pc+sun_vndr/gb(mod3)+inet(evdev)
geometry: sun(type6unix)
rules: evdev
model: sun_type6_unix_usb
layout: gb
variant: mod3

Evidently it was 'Trying to load rules file /usr/share/X11/xkb/rules/evdev...', but clearly it was still using the rules/evdev from /usr/share/X11/xkb (all of which can be confirmed by running both attempts with 'strace -e trace=open ...)

Note that there is some disagreement between the manpage and the -help as to whether there should be a space after the '-I'. The bug arises with and without that space. So this is a subsidiary bug in the -help, which ought to be fixed.

Note also that it thinks that it is in the 'C' locale, whereas I actually use 'en_GB.UTF-8'. This is another subsidiary bug; I have verified using gdb that there is no relevant call of 'getenv'.

Note also that is -I <directory> of xkbcomp appears to work correctly.

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