FULL PRODUCT VERSION :
java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Darwin colibri2.local 14.5.0 Darwin Kernel Version 14.5.0: Wed Jul 29 02:26:53 PDT 2015; root:xnu-2782.40.9~1/RELEASE_X86_64 x86_64

A DESCRIPTION OF THE PROBLEM :
Works in u51, fails in u60:

        NashornScriptEngine engine = (NashornScriptEngine) new ScriptEngineManager().getEngineByName("nashorn");
        ScriptContext otherCtxt = new SimpleScriptContext();
        engine.setContext(otherCtxt);
        otherCtxt.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
        engine.eval("aglobal = function(){return 12;};");
        // move code-to-reuse to global scope
        otherCtxt.setBindings(otherCtxt.getBindings(ScriptContext.ENGINE_SCOPE), ScriptContext.GLOBAL_SCOPE);
        // create throw-away engine scope
        otherCtxt.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
        engine.eval("alocal = function() {return aglobal();}");
        
        //////////////////////////// this fails suddenly
        engine.invokeFunction("alocal");
        //////////////////////////////////////////////////////////


/Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/bin/java …
Exception in thread "main" javax.script.ScriptException: ReferenceError: "aglobal" is not defined in <eval> at line number 1
at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:467)
at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:389)
at jdk.nashorn.api.scripting.NashornScriptEngine.invokeFunction(NashornScriptEngine.java:190)
at blah.TestMain.main(TestMain.java:33)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: <eval>:1 ReferenceError: "aglobal" is not defined
at jdk.nashorn.internal.runtime.ECMAErrors.error(ECMAErrors.java:57)
at jdk.nashorn.internal.runtime.ECMAErrors.referenceError(ECMAErrors.java:319)
at jdk.nashorn.internal.runtime.ECMAErrors.referenceError(ECMAErrors.java:291)
at jdk.nashorn.internal.objects.Global.__noSuchProperty__(Global.java:1432)
at jdk.nashorn.internal.scripts.Script$Recompilation$2$20$\^eval\_.alocal(<eval>:1)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:640)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:228)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
at jdk.nashorn.api.scripting.ScriptObjectMirror.callMember(ScriptObjectMirror.java:199)
at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:383)
... 7 more

REGRESSION. Last worked in version 8u51

ADDITIONAL REGRESSION INFORMATION:
java version "1.8.0_51"
Java(TM) SE Runtime Environment (build 1.8.0_51-b16)
Java HotSpot(TM) 64-Bit Server VM (build 25.51-b03, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
With u60:
        NashornScriptEngine engine = (NashornScriptEngine) new ScriptEngineManager().getEngineByName("nashorn");
        ScriptContext otherCtxt = new SimpleScriptContext();
        engine.setContext(otherCtxt);
        otherCtxt.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
        engine.eval("aglobal = function(){return 12;};");
        // move code-to-reuse to global scope
        otherCtxt.setBindings(otherCtxt.getBindings(ScriptContext.ENGINE_SCOPE), ScriptContext.GLOBAL_SCOPE);
        // create throw-away engine scope
        otherCtxt.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
        engine.eval("alocal = function() {return aglobal();}");
        
        //////////////////////////// this fails suddenly
        engine.invokeFunction("alocal");
        //////////////////////////////////////////////////////////

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No exception.
ACTUAL -
/Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/bin/java …
Exception in thread "main" javax.script.ScriptException: ReferenceError: "aglobal" is not defined in <eval> at line number 1
at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:467)
at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:389)
at jdk.nashorn.api.scripting.NashornScriptEngine.invokeFunction(NashornScriptEngine.java:190)
at blah.TestMain.main(TestMain.java:33)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: <eval>:1 ReferenceError: "aglobal" is not defined
at jdk.nashorn.internal.runtime.ECMAErrors.error(ECMAErrors.java:57)
at jdk.nashorn.internal.runtime.ECMAErrors.referenceError(ECMAErrors.java:319)
at jdk.nashorn.internal.runtime.ECMAErrors.referenceError(ECMAErrors.java:291)
at jdk.nashorn.internal.objects.Global.__noSuchProperty__(Global.java:1432)
at jdk.nashorn.internal.scripts.Script$Recompilation$2$20$\^eval\_.alocal(<eval>:1)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:640)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:228)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:393)
at jdk.nashorn.api.scripting.ScriptObjectMirror.callMember(ScriptObjectMirror.java:199)
at jdk.nashorn.api.scripting.NashornScriptEngine.invokeImpl(NashornScriptEngine.java:383)
... 7 more

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
@Test
public void testInvokeBug() {
NashornScriptEngine engine = (NashornScriptEngine) new ScriptEngineManager().getEngineByName("nashorn");
        ScriptContext otherCtxt = new SimpleScriptContext();
        engine.setContext(otherCtxt);
        otherCtxt.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
        engine.eval("aglobal = function(){return 12;};");
        // move code-to-reuse to global scope
        otherCtxt.setBindings(otherCtxt.getBindings(ScriptContext.ENGINE_SCOPE), ScriptContext.GLOBAL_SCOPE);
        // create throw-away engine scope
        otherCtxt.setBindings(engine.createBindings(), ScriptContext.ENGINE_SCOPE);
        engine.eval("alocal = function() {return aglobal();}");
        
        //////////////////////////// this fails suddenly
        engine.invokeFunction("alocal");
        //////////////////////////////////////////////////////////
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Use engine.eval("alocal()");
or
engine.compile(...)

But: cannot pass args to function, slower in my tests.