http://ea.jetbrains.com/browser/ea_problems/18809

python/src/com/jetbrains/python/run/AbstractPythonRunConfiguration.java

@@ -94,10 +94,12 @@ public abstract class AbstractPythonRunConfiguration extends ModuleBasedConfigur
     return sdkHome;
   }
 
+  @Nullable
   public String getInterpreterPath() {
     String sdkHome;
     if (myUseModuleSdk) {
       Sdk sdk = PythonSdkType.findPythonSdk(getModule());
+      if (sdk == null) return null;
       sdkHome = sdk.getHomePath();
     }
     else {

python/src/com/jetbrains/python/run/PythonCommandLineState.java

@@ -84,7 +84,7 @@ public abstract class PythonCommandLineState extends CommandLineState {
     return processHandler;
   }
 
-  protected GeneralCommandLine generateCommandLine() {
+  protected GeneralCommandLine generateCommandLine() throws ExecutionException {
     GeneralCommandLine commandLine = new GeneralCommandLine();
 
     setRunnerPath(commandLine);
@@ -96,8 +96,12 @@ public abstract class PythonCommandLineState extends CommandLineState {
     return commandLine;
   }
 
-  protected void setRunnerPath(GeneralCommandLine commandLine) {
-    commandLine.setExePath(myConfig.getInterpreterPath());
+  protected void setRunnerPath(GeneralCommandLine commandLine) throws ExecutionException {
+    String interpreterPath = myConfig.getInterpreterPath();
+    if (interpreterPath == null) {
+      throw new ExecutionException("Cannot find Python interpreter for this run configuration");
+    }
+    commandLine.setExePath(interpreterPath);
   }
 
   protected void buildCommandLineParameters(GeneralCommandLine commandLine) {

python/src/com/jetbrains/python/testing/PythonTestCommandLineStateBase.java

@@ -47,7 +47,7 @@ public abstract class PythonTestCommandLineStateBase extends PythonCommandLineSt
     return consoleView;
   }
 
-  protected GeneralCommandLine generateCommandLine() {
+  protected GeneralCommandLine generateCommandLine() throws ExecutionException {
     GeneralCommandLine cmd = new GeneralCommandLine();
 
     setRunnerPath(cmd);