For reproduce, please, run this code on Cygwin
$ jjs -scripting test.js
Current dir : C:\cygwin64\home\sqe\work\8u40\nashorn

Exception in thread "main" java.lang.RuntimeException: java.io.IOException: Cannot run program "notepad" (in directory "\home\sqe\work\8u40\nashorn"): CreateProcess error=267, The directory name is invalid
        at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:391)
        at jdk.nashorn.tools.Shell.apply(Shell.java:394)
        at jdk.nashorn.tools.Shell.runScripts(Shell.java:323)
        at jdk.nashorn.tools.Shell.run(Shell.java:169)
        at jdk.nashorn.tools.Shell.main(Shell.java:133)
        at jdk.nashorn.tools.Shell.main(Shell.java:112)
Caused by: java.io.IOException: Cannot run program "notepad" (in directory "\home\sqe\work\8u40\nashorn"): CreateProcess error=267, The directory name is invalid
        at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
        at jdk.nashorn.internal.runtime.ScriptingFunctions.exec(ScriptingFunctions.java:166)
        at jdk.nashorn.internal.scripts.Script$test.:program(test.js:7)
        at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:636)
        at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:229)
        at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:387)
        ... 5 more
Caused by: java.io.IOException: CreateProcess error=267, The directory name is invalid
        at java.lang.ProcessImpl.create(Native Method)
        at java.lang.ProcessImpl.<init>(ProcessImpl.java:386)
        at java.lang.ProcessImpl.start(ProcessImpl.java:137)
        at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
        ... 10 more


Code:
print("Current dir : " + java.lang.System.getProperty("user.dir"))

print("")

`notepad`

if I run command from ProcessBuilder, exception will not reproduce :

var pb = new java.lang.ProcessBuilder("notepad")
var p = pb.start()
p.waitFor()