File watching issues on Linux (tempdirs)

[Deraen]

Hi,

When trying tempdirs branch, I have problems with file watching. It seems that syncing files from source dirs to tempdirs is working but watch-task is broken. For some reason the watch-key is invalid.

Watch-service doesn't have any real changes on tempdirs branch so it could be that problem exists in master but is only triggered by something on tempdirs branch.

A watch key is created when a watchable object is registered with a watch service. The key remains valid until:

- It is cancelled, explicitly, by invoking its cancel method, or
- Cancelled implicitly, because the object is no longer accessible, or
- By closing the watch service.

I've been trying to debug this and I'm quite confident I have checked that none of those things are happening. I have added some debug prints to boot code and I have checked that

• isValid is called right after retrieving it from watchService so there is no chance of cancel being called?
• Dir being watched exists
• Watch service has not been closed

~/Source/boot-cljx tempdirs  2m 38s
❯ boot dev
Starting new-watch-service src
Sync (src)  ->  #<File .boot/tmp/k3b/rcesf6>
([:cp #<File src/deraen/boot_cljx/impl.clj> #<File .boot/tmp/k3b/rcesf6/deraen/boot_cljx/impl.clj>] [:cp #<File src/deraen/boot_cljx.clj> #<File .boot/tmp/k3b/rcesf6/deraen/boot_cljx.clj>])
Sync (src)  ->  #<File .boot/tmp/k3b/rcesf6>
()
Sync (src)  ->  #<File .boot/tmp/k3b/rcesf6>
()
Starting new-watch-service .boot/tmp/k3b/6qp7pj, .boot/tmp/k3b/rcesf6, .boot/tmp/k3b/-p9hf6h
Starting file watcher (CTRL-C to quit)...

Sync (src)  ->  #<File .boot/tmp/k3b/rcesf6>
()
#<LinuxWatchKey sun.nio.fs.LinuxWatchService$LinuxWatchKey@4eb69366> watchable #<UnixPath .boot/tmp/k3b/rcesf6/deraen/boot_cljx> is-valid false exists true
watch service: invalid watch key
nREPL server listening: 0.0.0.0:49714
Writing pom.xml and pom.properties...
Writing boot-cljx-0.2.0-SNAPSHOT.jar...
Installing boot-cljx-0.2.0-SNAPSHOT.jar...
([:cp #<File .boot/tmp/k3b/11lgcg/boot-cljx-0.2.0-SNAPSHOT.jar> #<File target/boot-cljx-0.2.0-SNAPSHOT.jar>])
Elapsed time: 4.538 sec

What should be the next steps in resolving this?
Can anyone else reproduce this? https://github.com/Deraen/boot-cljx/tree/tempdirs and running boot dev should print "watch service: invalid watch key"
If needed I think I could create virtualbox image to test this (or Vagrant script which can be used to create the image).