filelock error when using drake

[mattwarkentin]

Hi @gaborcsardi,

I am running into an issue when trying to use the {drake} package and it seems to be filelock related. The filelock error seems to be holding my drake project hostage, so to speak. I keep running into this error:

Error in filelock::lock(private$lock_file) : 
  Cannot lock file: '/Matt/.drake/drake/history/lock': Operation not supported
Error in filelock::unlock(lock) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'closure'

I really don't know enough about how filelock is used internally for drake, but I have worked with @wlandau to try and get to the bottom of it by running different bits of code to rule-in and out some issues. All of that can be found here ropensci/drake#1280

I am happy to continue to do whatever I can to help work toward a solution. Thanks for your help.

[wlandau]

Thanks for posting. Would you share the same reprex and lock file you posted to drake's issue tracker?

[mattwarkentin]

Here is a zip file from my drake project containing the lock file:
https://github.com/ropensci/drake/files/4815500/history.zip

Here is a minimal example reproducing the error:

library(filelock)
lock <- lock(".drake/drake/history/lock")
unlock(lock)

Error in lock(".drake/drake/history/lock") : 
  Cannot lock file: '/Volumes/hung_lab/shared/Matt/deep-learning/.drake/drake/history/lock': Operation not supported
Error in unlock(lock) : 
  VECTOR_ELT() can only be applied to a 'list', not a 'closure'

[gaborcsardi]

Well, sadly, that is not a reprex. I obviously do not have a .drake/drake/history/lock file.

[mattwarkentin]

You do if you download the zip file I also attached!

[gaborcsardi]

But I suspect that you are trying to create a lock file on some shared file system, and many of these, e.g. NFS, do not support locks.

[mattwarkentin]

It is the network drive at my hospital, so I would assumed that is a shared file system as you describe. I am not sure what NFS is.

[gaborcsardi]

https://en.wikipedia.org/wiki/Network_File_System

If this is macOS or some other Unix, and you type mount in a terminal, it will tell you the type of the file system. But it does not really matter. If you can use lock() in other directories, but cannot use locks on this file system, then based on the error message, the file system does not support locking.

A workaround would be to configure drake to store the lock files somewhere else, if that's possible.

[mattwarkentin]

For posterity, when running mount in the terminal

<<redcated info for mounted volume path>> (smbfs, nodev, nosuid, mounted by matt)

Hope this is helpful, @wlandau

[gaborcsardi]

Interesting, in theory SMBFS supports locking, AFAIK. In any case, being able to configure a custom directory for lock files is a good idea in general.

[mattwarkentin]

I don't know enough about this stuff, so I can't really offer much insight. But we seem to have identified the issue.

Running this on the mounted drive:

library(filelock)
lock <- lock("/Volumes/hung_lab/warkentin/lock")

Error in lock("/Volumes/hung_lab/warkentin/lock") : 
  Cannot lock file: '/Volumes/hung_lab/warkentin/lock': Operation not supported

On my internal drive, works fine.

library(filelock)
lock <- lock("/Volumes/Macintosh HD/Users/matt/Desktop/lock")
unlock(lock)

[1] TRUE

[wlandau]

Thanks for explaining, @gaborcsardi. I think I can solve this for drake via wlandau/txtq#18.

[wlandau]

And @mattwarkentin, thanks for #26 (comment). That makes it clear we need wlandau/txtq#18.

[wlandau]

Would you try ropensci/drake@2ffd42a? It should be fixed now because I made drake avoid file locking altogether (via an update I just made to txtq).

[pydupont]

It works. Thanks for your work!