That's quite the regression, sorry.

Could you please post the output of these commands on the "Script Console"?

println System.getenv("ANDROID_SDK_HOME")
println System.getenv("ANDROID_SDK_ROOT")
println System.getenv("ANDROID_HOME")
println System.getenv("USERPROFILE")
println System.getenv("HUDSON_HOME")
println System.getenv("USERNAME")
println System.getProperty("user.home")

Also, are you running a Hudson as a service on Windows, or via a different means?

Here's the output:
null
null
D:\tools\android-sdk-windows
C:\Documents and Settings\Default User
d:\hudson
null
C:\Documents and Settings\Default User

Hudson runs as a service.

Thanks for the info.

I notice that the log output doesn't claim that it created a new AVD, meaning the plugin found an existing one.

Do you know where the AVD is located, and does this differ from where AVDs are created if you run 'android create avd' manually as the Hudson user?

Actually, that was the output from the third trial. I have just checked the avd folder to see whether the AVD was created. And, it was:

Directory of C:\Documents and Settings\Default User\.android\avd
09/03/2010 04:51 PM <DIR> .
09/03/2010 04:51 PM <DIR> ..
09/03/2010 04:51 PM <DIR> hudson_en-US_160_WVGA_android-7.avd
09/03/2010 04:51 PM 110 hudson_en-US_160_WVGA_android-7.ini
1 File(s) 110 bytes

Here's the output from the first run:
[android] Using Android SDK: d:\tools\android-sdk-windows
[android] Creating Android AVD at C:\Documents and Settings\Default User\.android\avd\hudson_en-US_160_WVGA_android-7.avd
[android] Starting Android emulator
$ d:\tools\android-sdk-windows/tools/emulator.exe -ports 2711,2712 -no-boot-anim -prop persist.sys.language=en -prop persist.sys.country=US -avd hudson_en-US_160_WVGA_android-7
emulator: ERROR: unknown virtual device name: 'hudson_en-US_160_WVGA_android-7'
emulator: could not find virtual device named 'hudson_en-US_160_WVGA_android-7'
[android] Emulator did not appear to start; giving up
[android] Stopping Android emulator

By default, Windows services run using a special user "Local System".
Now, I have created a special user in order to check what you have asked. If Hudson runs with this user everything seems to be ok.

Ok, thanks for confirming this. I did have a couple of other people report similar issues to me in the past. I hadn't seen it myself on Windows, as I use a "hudson" role account to run the service.

As far as I can determine, this is a bug on Android's part – the Java-based `android` tool which creates AVDs in a certain directory (determined by environment variables and Java properties), whereas the C-based `emulator` seems to rely on a Win32 API call to retrieve a known user profile directory.

I imagine that there is a subtle difference between the two when run as a service.

Someone can feel free to investigate further in the AOSP and submit a patch.

Meanwhile, I have added this as a known issue on the wiki.

Closing this as "won't fix" as I don't believe there's anything that can be done in the plugin just now.