Hmm. I fixed this about a year ago when SDK Tools r17 came out:
https://github.com/jenkinsci/android-emulator-plugin/commit/4a1fee5

I couldn't reproduce this just now with the plugin installing the SDK.
I did once see a bug where `sdk.getSdkToolsVersion()` returned the wrong value, but I fixed that recently (I believe).
And from your log it seems that the plugin is using the just-installed SDK as expected, so I'm not sure what's going wrong there..

I guess you're using the latest plugin version (plus the Serializable fix), on OS X.
Do you have another Android SDK configured in the global Jenkins properties, an Android SDK in your PATH, ANDROID_HOME etc.?

Well, in the log my laptop is a slave for the Jenkins master that runs on Ubuntu, but I've seen the same error when provisioning a new EC2 instance, but I can check again to be sure.

I checked the settings on the master and that doesn't have ANDROID_SDK_ROOT configured (it's empty). The master doesn't have an Android SDK installed, it's too weak to build anything

Maybe this is related to running as a slave, e.g. version check is on the master, not the slave?

I was testing this yesterday with a slave, but yeah I'll also try again with a completely different machine, e.g. starting on a new EC2 instance.

I believe all the SdkInstaller code runs together on the slave, but I'll double-check.

I can verify that it looks like the check SdkInstaller.java String all = sdk.getSdkToolsVersion() looks like it runs only on the master and not on the slave where the tools are installed. Tried to build on both a macosx slave and an linux slave with no success getting the sdk to install.

Switched over to running this on master and it works. I have seen some mention of running commands like this on the slave via an jenkins api call.

I was trying to update to the latest tools version so I could then run API 17 on Jekins. I experienced the same issue. Our set up is - jenkins runs on top of a OpenIndiana host, over SSH it connects to a Linux slave. The Linux slave is where the SDK and all the installed tools live..

Here is our log message:

[android] No Android SDK found; let's install it automatically...
Downloading and installing Android SDK from http://dl.google.com/android/android-sdk_r21.0.1-linux.tgz
[android] Base SDK installed successfully
[android] Going to install required Android SDK components...
[android] Installing the 'platform-tool,tool' SDK component(s)...
$ /home/jenkins/tools/android-sdk/tools/android update sdk -u -o -t platform-tool,tool
Error: Flag '-o' is not valid for 'update sdk'.

Usage:
android [global options] update sdk [action options]
Global options:
-h --help : Help on a specific command.
-v --verbose : Verbose mode, shows errors, warnings and all messages.
--clear-cache: Clear the SDK Manager repository manifest cache.
-s --silent : Silent mode, shows errors only.

Action "update sdk":
Updates the SDK by suggesting new platforms to install if available.
Options:
--proxy-port: HTTP/HTTPS proxy port (overrides settings if defined)
--proxy-host: HTTP/HTTPS proxy host (overrides settings if defined)
-s --no-https : Uses HTTP instead of HTTPS (the default) for downloads.
-a --all : Includes all packages (such as obsolete and non-dependent
ones.)
-f --force : Forces replacement of a package or its parts, even if
something has been modified.
-u --no-ui : Updates from command-line (does not display the GUI)
-p --obsolete : Deprecated. Please use --all instead.
-t --filter : A filter that limits the update to the specified types of
packages in the form of a comma-separated list of
[platform, system-image, tool, platform-tool, doc, sample,
source]. This also accepts the identifiers returned by
'list sdk --extended'.
-n --dry-mode : Simulates the update but does not download or install
anything.
ERROR: Processing failed due to a bug in the code. Please report this to jenkinsci-users@googlegroups.com
java.lang.NullPointerException
at hudson.plugins.android_emulator.util.Utils.getToolCommand(Utils.java:369)
at hudson.plugins.android_emulator.util.Utils.runAndroidTool(Utils.java:413)
at hudson.plugins.android_emulator.util.Utils.runAndroidTool(Utils.java:406)
at hudson.plugins.android_emulator.SdkInstaller.isPlatformInstalled(SdkInstaller.java:258)
at hudson.plugins.android_emulator.SdkInstaller.installPlatform(SdkInstaller.java:205)
at hudson.plugins.android_emulator.SdkInstaller.installPlatform(SdkInstaller.java:190)
at hudson.plugins.android_emulator.SdkInstaller.installDependencies(SdkInstaller.java:177)
at hudson.plugins.android_emulator.AndroidEmulator.setUp(AndroidEmulator.java:250)
at hudson.maven.MavenModuleSetBuild$MavenModuleSetBuildExecution.doRun(MavenModuleSetBuild.java:600)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:580)
at hudson.model.Run.execute(Run.java:1575)
at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:477)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:237)
project=hudson.maven.MavenModuleSet@1a42f7f[absio-android-IT-4.2]
project.getModules()=[]
project.getRootModule()=null
FATAL: null
java.lang.NullPointerException
at hudson.plugins.android_emulator.util.Utils.getToolCommand(Utils.java:369)
at hudson.plugins.android_emulator.util.Utils.runAndroidTool(Utils.java:413)
at hudson.plugins.android_emulator.util.Utils.runAndroidTool(Utils.java:406)
at hudson.plugins.android_emulator.SdkInstaller.isPlatformInstalled(SdkInstaller.java:258)
at hudson.plugins.android_emulator.SdkInstaller.installPlatform(SdkInstaller.java:205)
at hudson.plugins.android_emulator.SdkInstaller.installPlatform(SdkInstaller.java:190)
at hudson.plugins.android_emulator.SdkInstaller.installDependencies(SdkInstaller.java:177)
at hudson.plugins.android_emulator.AndroidEmulator.setUp(AndroidEmulator.java:250)
at hudson.maven.MavenModuleSetBuild$MavenModuleSetBuildExecution.doRun(MavenModuleSetBuild.java:600)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:580)
at hudson.model.Run.execute(Run.java:1575)
at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:477)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:237)

Code changed in jenkins
User: Christopher Orr
Path:
src/main/java/hudson/plugins/android_emulator/SdkInstaller.java
src/main/java/hudson/plugins/android_emulator/sdk/AndroidSdk.java
http://jenkins-ci.org/commit/android-emulator-plugin/0bee4d3602a7d46a898f8c30cfb4b6572e814c30
Log:
[FIXED JENKINS-16720] Ensure SDK version check is done on the right node.

Previously, when automatically installing the SDK, we were instantiating
an SDK object on the master, meaning that we were inspecting the tools
version file on the master, rather than on the node in question.

Also removed the empty catch block which was masking this problem.

Compare: https://github.com/jenkinsci/android-emulator-plugin/compare/2035f3c789b7...0bee4d3602a7

Version 2.9 has been released, which includes this fix.