Error removing intermediate container

[raamana]

In my recent attempts (see: [https://circleci.com/gh/BIDS-Apps/oppni/38]), I see the following error. Doesn't seem bad, something to be fixed nonetheless. Any ideas @chrisfilo ?

Error removing intermediate container 29cfe2fb0937: 
Cannot destroy container 29cfe2fb093757b0ba67074db02d64c1fcd4641bb882e74dec032a76529fbe05: 
Driver btrfs failed to remove root filesystem 29cfe2fb093757b0ba67074db02d64c1fcd4641bb882e74dec032a76529fbe05: 
Failed to destroy btrfs snapshot: operation not permitted

[chrisgorgo]

This is normal and can be ignored: https://circleci.com/docs/docker-btrfs-error/

[raamana]

Thanks.