udevd daemon run with --debug affects output of 'udevadm info'

Binary package hint: udev

On lucid, I've added the following rule in /etc/udev/rules.d/85-foo.rules:
ACTION=="add", RUN+="/tmp/foo"

then, /tmp/foo has:
#!/bin/sh
udevadm info --export-db > ${0}.stdout 2>${0}.stderr

if I run udevd with '--debug --debug-trace', then /tmp/foo.stderr will have content. If I run without --debug and --debug-trace, then foo.stderr has no content.

An example of the content in /tmp/foo.stderr is:

custom logging function 0x7f6c8bd1a010 registered
selinux=0
calling: info
device 0x7f6c8bd24d30 has devpath '/devices/LNXSYSTM:00'
device 0x7f6c8bd24d30 has devpath '/devices/LNXSYSTM:00/LNXCPU:00'
device 0x7f6c8bd24d30 has devpath '/devices/LNXSYSTM:00/LNXPWRBN:00'
...
device 0x7f6c8bd24d50 has devpath '/devices/virtual/vtconsole/vtcon0'
device 0x7f6c8bd24d50 has devpath '/devices/virtual/vtconsole/vtcon1'
device 0x7f6c8bd24d50 has devpath '/devices/virtual/block/md0'
device 0x7f6c8bd24d50 filled with db symlink data '/dev/md0'

Essentially, the flags that the udev daemon are run with affect the stderr of something that is run via a udev hook.

This is causing a problem for a program that is parsing 'udevadm info' output from a udev hook. Obviously it can be worked around by not having the program parsing that output join udevadm's stdout and stderr, but I believe this is buggy behavior none the less.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: udev 151-12
ProcVersionSignature: User Name 2.6.34-4.11-virtual 2.6.34
Uname: Linux 2.6.34-4-virtual x86_64
Architecture: amd64
CustomUdevRuleFiles: 85-ebsmount.rules
Date: Tue Jun 8 21:00:32 2010
Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: Bochs Bochs
ProcCmdLine: root=/dev/sda1 console=ttyS0
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: udev
dmi.bios.date: 01/01/2007
dmi.bios.vendor: Bochs
dmi.bios.version: Bochs
dmi.chassis.type: 1
dmi.chassis.vendor: Bochs
dmi.modalias: dmi:bvnBochs:bvrBochs:bd01/01/2007:svnBochs:pnBochs:pvr:cvnBochs:ct1:cvr:
dmi.product.name: Bochs
dmi.sys.vendor: Bochs