Testing for a virtual device can be useful for a variety of features not or poorly working in those, for instance push notifications (last time I tried it just seemed to block the execution) or the camera (as mentioned in this post, on a virtual device you could replace the camera with a “fake” one by loading a picture from the disk).

The Ti.Platform.model variable should contain all you need to determine whether or not you’re running on a real device. On the iOS simulator it will return “Simulator”, on an Android emulator it will return something like “google_sdk”. So a way to test for it would be simply:

if (Ti.Platform.model === 'Simulator'
 || Ti.Platform.model.indexOf('sdk') !== -1 ){
    alert('This is a virtual device');
}

(sorry for the poor indentation, WordPress makes it pretty tough :s)

Sources:
https://developer.appcelerator.com/question/63871/way-to-detect-running-in-simulator
http://docs.appcelerator.com/titanium/latest/#!/api/Titanium.Platform-property-model

I believe this error message is quite standard at the end of a failed build in Titanium:
[ERROR] Application Installer abnormal process termination. Process exit value was 1

A probably rarer sight is when this occurs very early in the build, when few to none previous build messages are available to provide any clue on what the heck is happening. I had one of those lately, a failed build after just one single, unhelpful message, with a complete log consisting of just:
Titanium Command-Line Interface, CLI version 3.4.0, Titanium SDK version 3.4.0.GA
Copyright (c) 2012-2014, Appcelerator, Inc. All Rights Reserved.
Please report bugs to http://jira.appcelerator.org/
[INFO] : Found Titanium module id=ti.draggable version=1.0 platform=android deploy-type=test path=D:\PROG\PROGRAMMING\xxxxx\modules\android\ti.draggable\1.0
[ERROR] Application Installer abnormal process termination. Process exit value was 1

So I just searched for any possible solution, and gladly the first suggestion I found was a good one: simply delete the whole “build” folder, so as to recompile a whole new build from scratch (some corrupted temporary build file(s) I guess). Deleting the build folder, however, turned out to be quite a pain: I had permissions issue, Windows telling me I should be an administrator to delete that folder, even though I was one. I ended up booting to Linux just to delete that nasty folder (if you don’t have a dual boot, I guess you just won a live DVD ;)), but it worked, and so did the compilation.

Source, with additional possible fixes (although some of those were given as a solution to much more verbose build logs) is here: http://developer.appcelerator.com/question/142108/error-application-installer-abnormal-process-termination-process-exit-value-was-1

Edit a few hours later: Titanium really has a lot of potential generating such shitty errors. Another common sight is "build\android\build-manifest.json does not exist in Titanium Studio". Same kind of mess, same kind of fix. Note that another option is to use Project → Clean, but for me it didn’t work because that Titanium idiot somehow managed to create a file (I think that was build\android\assets\app.js) that it’s not able to delete itself. Even more options are presented in this stackoverflow post. Good luck, we all need it with those massively stochastic errors :s

It seems that with every Titanium upgrade comes a bunch of big, annoying issues. I just upgraded from Titanium 3.3.0 to 3.4.0, and this time the issue was Titanium wouldn’t see the Android SDK anymore. The proper error message was well hidden, at first all I could see was that Titanium wasn’t able to find my debugging device (and external LG 975) anymore. After upgrading the Android SDK (a few minor upgrades I believe) and messing around in the options, I eventually found a proper error message in Preferences → Studio → Platforms → Android (note that I have absolutely no idea how to reach that Preferences window without using the tool icon next to the OSes under “Deployment Targets” in the tiapp.xml GUI editor): “[Android SDK Home] No Android SDKs were found under the specified SDK location”.

So, Titanium couldn’t see the Android SDK, even though I indicated the proper path (very same as the one used with the previous version). Puzzling, as usual…

I found people mentioning this issue when upgrading to Titanium 3.2 from 3.1. Not really my case, but now I know/suppose that’s a recurring issue.

Then I found someone mentioning I should delete a specific config file, namely C:/Users/[username]/.titanium/config.json. I did, and it worked. As I was curious, I kept a copy of the old version, and then compared it to the new version. The only difference is that the new version removed an item at the end. The old version was:

{
	"user": {
		"locale": "en-us"
	},
	"app": {
		"workspace": ""
	},
	"cli": {
		"colors": true,
		"completion": false,
		"logLevel": "trace",
		"prompt": true,
		"progressBars": true,
		"failOnWrongSDK": false,
		"httpProxyServer": "",
		"rejectUnauthorized": true,
		"width": 100,
		"ignoreDirs": "^(\\.svn|_svn|\\.git|\\.hg|\\.?[Cc][Vv][Ss]|\\.bzr|\\$RECYCLE\\.BIN)$",
		"ignoreFiles": "^(\\.gitignore|\\.npmignore|\\.cvsignore|\\.DS_Store|\\._.*|[Tt]humbs.db|\\.vspscc|\\.vssscc|\\.sublime-project|\\.sublime-workspace|\\.project|\\.tmproj)$"
	},
	"paths": {
		"commands": [],
		"hooks": [],
		"modules": [],
		"plugins": [],
		"sdks": [
			"C:\\Users\\Admin\\AppData\\Roaming\\Titanium"
		],
		"templates": []
	},
	"android": {
		"sdkPath": "D:\\PROG\\PROGRAMMING\\adt-bundle-windows-x86_64\\sdk"
	},
	"sdk": {
		"selected": "3.3.0.GA"
	}
}

and the new version removed

	"sdk": {
		"selected": "3.3.0.GA"
	}

Source is here, and contains a few other things to try, in case this one doesn’t work for you…

I recently upgraded Titanium, and possibly also my Android SDK (this is getting a bit messy, with the old SDK, used by Titanium, living along with the new SDK brought by the new, beta, Android Studio). And when compiling an app for Android, which I hadn’t done in a long while, I encountered this error:

[ERROR] : Unable to find Android SDK tools: zipalign.
[ERROR] : You have an incomplete or out-of-date installation.
[ERROR] : Verify your Android SDK packages or reinstall the Android SDK by running titanium setup android or manually downloading from http://appcelerator.com/android-sdk.

I opened the Android SDK manager, but no obvious package seemed to be missing. Finally, I found someone suggesting to move around that “zipalign” tool itself. So, I eventually found zipalign.exe in adt-bundle-windows-x86_64\sdk\build-tools\android-4.4W, and copied it into adt-bundle-windows-x86_64\sdk\tools. Success! 🙂

Also, thanks very much to the guy who posted a close enough answer there: http://developer.appcelerator.com/question/175598. Too bad his answer wasn’t marked as the proper solution, the chosen one is rubbish…