LinuxPidEnumerator throws if process is killed during enumeration

[cxcorp]

Exception in thread "main" java.io.UncheckedIOException: java.nio.file.NoSuchFileException: /proc/31572
	at java.nio.file.FileTreeIterator.fetchNextIfNeeded(FileTreeIterator.java:88)
	at java.nio.file.FileTreeIterator.hasNext(FileTreeIterator.java:104)
	at java.util.Iterator.forEachRemaining(Iterator.java:115)
	at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
	at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
	at cx.corp.lacuna.core.linux.LinuxPidEnumerator.getPids(LinuxPidEnumerator.java:38)
	at cx.corp.lacuna.core.NativeProcessEnumeratorImpl.getProcesses(NativeProcessEnumeratorImpl.java:24)
	at cx.corp.lacuna.Main.main(Main.java:58)
Caused by: java.nio.file.NoSuchFileException: /proc/31572
	at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
	at sun.nio.fs.UnixFileAttributeViews$Basic.readAttributes(UnixFileAttributeViews.java:55)
	at sun.nio.fs.UnixFileSystemProvider.readAttributes(UnixFileSystemProvider.java:144)
	at sun.nio.fs.LinuxFileSystemProvider.readAttributes(LinuxFileSystemProvider.java:99)
	at java.nio.file.Files.readAttributes(Files.java:1737)
	at java.nio.file.FileTreeWalker.getAttributes(FileTreeWalker.java:219)
	at java.nio.file.FileTreeWalker.visit(FileTreeWalker.java:276)
	at java.nio.file.FileTreeWalker.next(FileTreeWalker.java:372)
	at java.nio.file.FileTreeIterator.fetchNextIfNeeded(FileTreeIterator.java:84)
	... 11 more

[cxcorp]

Files.walk is broken http://stackoverflow.com/a/22868706/996081