(Sandbox) Caught a bad syscall attempt (syscall chown)

On 0.2.8.1-alpha:

tor --defaults-torrc /usr/share/tor/tor-service-defaults-torrc -f /etc/tor/torrc --RunAsDaemon 0

tail -F /var/log/tor/log
[..]
Feb 05 23:15:14.000 [notice] Bootstrapped 0%: Starting
Feb 05 23:15:14.000 [notice] Bootstrapped 80%: Connecting to the Tor network
Feb 05 23:15:14.000 [notice] Bootstrapped 85%: Finishing handshake with first hop
Feb 05 23:15:15.000 [warn] sandbox_intern_string(): Bug: No interned sandbox parameter found for /var/run/tor (on Tor 0.2.8.1-alpha )
Feb 05 23:15:15.000 [notice] Opening Control listener on /var/run/tor/control

============================================================ T= 1454710515
(Sandbox) Caught a bad syscall attempt (syscall chown)
tor(+0x14ca96)[0x7f76431b4a96]
/lib/x86_64-linux-gnu/libc.so.6(chown+0x7)[0x7f764155bf07]
/lib/x86_64-linux-gnu/libc.so.6(chown+0x7)[0x7f764155bf07]
tor(retry_all_listeners+0x80e)[0x7f764314d14e]
tor(+0x3cf1d)[0x7f76430a4f1d]
tor(+0x56108)[0x7f76430be108]
tor(+0x3d34c)[0x7f76430a534c]
/usr/lib/x86_64-linux-gnu/libevent-2.0.so.5(+0x12584)[0x7f76426f3584]
/usr/lib/x86_64-linux-gnu/libevent-2.0.so.5(event_base_loop+0x7fc)[0x7f76426f13dc]
tor(do_main_loop+0x274)[0x7f76430a8d34]
tor(tor_main+0x1a55)[0x7f76430ac355]
tor(main+0x19)[0x7f76430a4979]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5)[0x7f76414a0b45]
tor(+0x3c9c9)[0x7f76430a49c9]

This doesn't happen on 0.2.7.x