Problems updating linux dedicated server with steam

[Radon]

Since the last update, i wanted to update our dedicated server as well, as usual i tried:

./steam -command update -game killingfloor -dir kf-mykfserver

But the update script stays at "Updating Installation" for hours without any process.
If i abort and try again, the updater seems to clean some temp files before trying again, with the same result that it hangs by "Updating Installation".

Checking bootstrapper version ...
Updating Installation
removing stale semaphore last operated on by process 7412 with name 0eBlobRegistryMutex_58C62B72A4136827FD85ED40F58070 4D
removing stale semaphore last operated on by process 7412 with name 0eBlobRegistrySignal_58C62B72A4136827FD85ED40F5807 04D

I re-downloaded hldsupdate tool, steam, tried installing a new server with specifying an empty directory with the above command, but nothing.
TF2 servers can be updated successfully, tried this yesterday, only KF fails.

Any ideas for this?

working on a latest ubuntu distri


btw, this is a crosspost from Steam Forums, i don't know where's the best place to get support for this problem