tor fails to start with 'Sandbox 1'
OS: CentOS 7
SELinux: disabled
tor-0.2.9.10-1.el7.x86_64
```
============================================================
(Sandbox) Caught a bad syscall attempt (syscall fchmod)
/usr/bin/tor(+0x15d83a)[0x7ff9aa58b83a]
/lib64/libc.so.6(fchmod+0x7)[0x7ff9a8b1a917]
/lib64/libc.so.6(fchmod+0x7)[0x7ff9a8b1a917]
/usr/bin/tor(check_private_dir+0x151)[0x7ff9aa584741]
/usr/bin/tor(init_keys+0x9b)[0x7ff9aa4b6cab]
/usr/bin/tor(do_main_loop+0x4b)[0x7ff9aa472b1b]
/usr/bin/tor(tor_main+0x1c25)[0x7ff9aa4763a5]
/usr/bin/tor(main+0x19)[0x7ff9aa46e8c9]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x7ff9a8a53b35]
/usr/bin/tor(+0x4091b)[0x7ff9aa46e91b]
```
torrc:
```
OfflineMasterKey 1
RunAsDaemon 0
Log notice syslog
OutboundBindAddress ...
SocksPort 0
User ...
DataDirectory /var/lib/tor-instances/...
ORPort ...
DirPort ...
SyslogIdentityTag ...
Nickname ...
ControlSocket 0
CookieAuthentication 0
ExitRelay 0
ExitPolicy reject *:*
Sandbox 1
ShutdownWaitLength 1
```
issue