fuse: unknown option `slave'

[mika018]

I am trying to mount the vm folder to a host directory using:
vm1a.vm.synced_folder "/path/on/my/machine", "/path/on/vm", type: "sshfs"
But I got an error saying that I have to use nonempty flag which I added and now my Vagrantfile looks like this:
vm1a.vm.synced_folder "/path/on/my/machine", "/path/on/vm", sshfs_opts_append: "-o nonempty", type: "sshfs"
When trying to get the sshfs running using vagrant sshfs --mount and after printing Checking Mount... for like 7 times this error is printed:

Mounting SSHFS shared folder via slave SSHFS mount failed. Please
look at the below STDERR output from the processes that were run.

SSH command:

Warning: Permanently added '[127.0.0.1]:2201' (ECDSA) to the list of known hosts.
fuse: unknown option `slave'

SFTP command:

I couldn't find any issue reporting this nor useful resources online. Any ideas?

[dustymabe]

What is the target vagrant box operating system? I'm guessing the version of sshfs you have doesn't support the -o slave option. Maybe check the man page to see.

[dustymabe]

For a summary of what is going on read this section from the README

[dustymabe]

Closing this pending more information.