title: Run-android build failed for react native project due to not finding tools.jar
body: <p>I was following a youtube video on installing react native and completely new to this. I put in the command to run-android for react native project and a build error popped up saying I'm missing tools.jar. I saw a previous support thread on here saying that the person didn't have Android Support Repository but I do have it installed. Here's the error</p>
  
  <pre><code>Starting JS server...
  Starting the packager in a new window is not supported on Windows yet.
  Please start it manually using 'react-native start'.
  We believe the best Windows support will come from a community of people
  using React Native on Windows on a daily basis.
  Would you be up for sending a pull request?
  Building and installing the app on the device (cd android &amp;&amp; gradlew.bat installDebug)...
  Download https://jcenter.bintray.com/net/sf/proguard/proguard-gradle/5.2.1/proguard-gradle-5.2.1.pom
  Download https://jcenter.bintray.com/net/sf/proguard/proguard-parent/5.2.1/proguard-parent-5.2.1.pom
  Download https://jcenter.bintray.com/com/squareup/javawriter/2.5.0/javawriter-2.5.0.pom
  Download https://jcenter.bintray.com/org/bouncycastle/bcpkix-jdk15on/1.48/bcpkix-jdk15on-1.48.pom
  Download https://jcenter.bintray.com/org/bouncycastle/bcprov-jdk15on/1.48/bcprov-jdk15on-1.48.pom
  Download https://jcenter.bintray.com/org/ow2/asm/asm/5.0.3/asm-5.0.3.pom
  Download https://jcenter.bintray.com/org/ow2/asm/asm-parent/5.0.3/asm-parent-5.0.3.pom
  Download https://jcenter.bintray.com/org/ow2/ow2/1.3/ow2-1.3.pom
  Download https://jcenter.bintray.com/org/ow2/asm/asm-tree/5.0.3/asm-tree-5.0.3.pom
  Download https://jcenter.bintray.com/com/android/tools/jack/jack-api/0.9.0/jack-api-0.9.0.pom
  Download https://jcenter.bintray.com/com/android/tools/jill/jill-api/0.9.0/jill-api-0.9.0.pom
  Download https://jcenter.bintray.com/org/eclipse/jdt/core/compiler/ecj/4.4.2/ecj-4.4.2.pom
  Download https://jcenter.bintray.com/net/sf/proguard/proguard-base/5.2.1/proguard-base-5.2.1.pom
  Download https://jcenter.bintray.com/com/google/code/gson/gson/2.2.4/gson-2.2.4.pom
  Download https://jcenter.bintray.com/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.pom
  Download https://jcenter.bintray.com/org/apache/commons/commons-parent/33/commons-parent-33.pom
  Download https://jcenter.bintray.com/org/apache/apache/13/apache-13.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpclient/4.1.1/httpclient-4.1.1.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcomponents-client/4.1.1/httpcomponents-client-4.1.1.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/project/4.1.1/project-4.1.1.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpmime/4.1/httpmime-4.1.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcomponents-client/4.1/httpcomponents-client-4.1.pom
  Download https://jcenter.bintray.com/com/google/guava/guava/17.0/guava-17.0.pom
  Download https://jcenter.bintray.com/com/google/guava/guava-parent/17.0/guava-parent-17.0.pom
  Download https://jcenter.bintray.com/net/sf/kxml/kxml2/2.3.0/kxml2-2.3.0.pom
  Download https://jcenter.bintray.com/org/ow2/asm/asm-analysis/5.0.3/asm-analysis-5.0.3.pom
  Download https://jcenter.bintray.com/com/intellij/annotations/12.0/annotations-12.0.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcore/4.1/httpcore-4.1.pom
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcomponents-core/4.1/httpcomponents-core-4.1.pom
  Download https://jcenter.bintray.com/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.pom
  Download https://jcenter.bintray.com/org/apache/commons/commons-parent/5/commons-parent-5.pom
  Download https://jcenter.bintray.com/commons-codec/commons-codec/1.4/commons-codec-1.4.pom
  Download https://jcenter.bintray.com/com/android/tools/external/lombok/lombok-ast/0.2.3/lombok-ast-0.2.3.pom
  Download https://jcenter.bintray.com/net/sf/proguard/proguard-gradle/5.2.1/proguard-gradle-5.2.1.jar
  Download https://jcenter.bintray.com/com/squareup/javawriter/2.5.0/javawriter-2.5.0.jar
  Download https://jcenter.bintray.com/org/bouncycastle/bcpkix-jdk15on/1.48/bcpkix-jdk15on-1.48.jar
  Download https://jcenter.bintray.com/org/bouncycastle/bcprov-jdk15on/1.48/bcprov-jdk15on-1.48.jar
  Download https://jcenter.bintray.com/org/ow2/asm/asm/5.0.3/asm-5.0.3.jar
  Download https://jcenter.bintray.com/org/ow2/asm/asm-tree/5.0.3/asm-tree-5.0.3.jar
  Download https://jcenter.bintray.com/com/android/tools/jack/jack-api/0.9.0/jack-api-0.9.0.jar
  Download https://jcenter.bintray.com/com/android/tools/jill/jill-api/0.9.0/jill-api-0.9.0.jar
  Download https://jcenter.bintray.com/org/eclipse/jdt/core/compiler/ecj/4.4.2/ecj-4.4.2.jar
  Download https://jcenter.bintray.com/net/sf/proguard/proguard-base/5.2.1/proguard-base-5.2.1.jar
  Download https://jcenter.bintray.com/com/google/code/gson/gson/2.2.4/gson-2.2.4.jar
  Download https://jcenter.bintray.com/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.jar
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpclient/4.1.1/httpclient-4.1.1.jar
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpmime/4.1/httpmime-4.1.jar
  Download https://jcenter.bintray.com/com/google/guava/guava/17.0/guava-17.0.jar
  Download https://jcenter.bintray.com/net/sf/kxml/kxml2/2.3.0/kxml2-2.3.0.jar
  Download https://jcenter.bintray.com/org/ow2/asm/asm-analysis/5.0.3/asm-analysis-5.0.3.jar
  Download https://jcenter.bintray.com/com/intellij/annotations/12.0/annotations-12.0.jar
  Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcore/4.1/httpcore-4.1.jar
  Download https://jcenter.bintray.com/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar
  Download https://jcenter.bintray.com/commons-codec/commons-codec/1.4/commons-codec-1.4.jar
  Download https://jcenter.bintray.com/com/android/tools/external/lombok/lombok-ast/0.2.3/lombok-ast-0.2.3.jar
  :app:preBuild UP-TO-DATE
  :app:preDebugBuild UP-TO-DATE
  :app:checkDebugManifest
  :app:preReleaseBuild UP-TO-DATE
  :app:prepareComAndroidSupportAppcompatV72301Library UP-TO-DATE
  :app:prepareComAndroidSupportRecyclerviewV72301Library UP-TO-DATE
  :app:prepareComAndroidSupportSupportV42301Library UP-TO-DATE
  :app:prepareComFacebookFrescoDrawee081Library UP-TO-DATE
  :app:prepareComFacebookFrescoFbcore081Library UP-TO-DATE
  :app:prepareComFacebookFrescoFresco081Library UP-TO-DATE
  :app:prepareComFacebookFrescoImagepipeline081Library UP-TO-DATE
  :app:prepareComFacebookFrescoImagepipelineOkhttp081Library UP-TO-DATE
  :app:prepareComFacebookReactReactNative0191Library UP-TO-DATE
  :app:prepareOrgWebkitAndroidJscR174650Library UP-TO-DATE
  :app:prepareDebugDependencies
  :app:compileDebugAidl UP-TO-DATE
  :app:compileDebugRenderscript UP-TO-DATE
  :app:generateDebugBuildConfig UP-TO-DATE
  :app:generateDebugAssets UP-TO-DATE
  :app:mergeDebugAssets UP-TO-DATE
  :app:generateDebugResValues UP-TO-DATE
  :app:generateDebugResources UP-TO-DATE
  :app:mergeDebugResources UP-TO-DATE
  :app:bundleDebugJsAndAssets SKIPPED
  :app:processDebugManifest UP-TO-DATE
  :app:processDebugResources UP-TO-DATE
  :app:generateDebugSources UP-TO-DATE
  :app:processDebugJavaRes UP-TO-DATE
  :app:compileDebugJavaWithJavac FAILED
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':app:compileDebugJavaWithJavac'.
  &gt; Could not find tools.jar
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  
  BUILD FAILED
  
  Total time: 30.123 secs
  Could not install the app on the device, read the error above for details.
  Make sure you have an Android emulator running or a device connected and have
  set up your Android development environment:
  https://facebook.github.io/react-native/docs/android-setup.html
  </code></pre>
  
  <p>I appreciate any help. And if it's possible, can I get simple instructions, a lot of this stuff is new to me but I'll try.</p>