XXR could not start, system log as follows:

[chd1998]

Wed Dec 18 11:20:14 2019 user.notice shadowsocksr: ssr redir tcp error.restart!
Wed Dec 18 11:20:15 2019 daemon.warn pdnsd[18610]: Caught signal 15. Exiting.
Wed Dec 18 11:20:19 2019 cron.err crond[19946]: crond (busybox 1.31.1) started, log level 8
Wed Dec 18 11:20:21 2019 daemon.info pdnsd[20212]: pdnsd-1.2.9b-par starting.
Wed Dec 18 11:20:25 2019 cron.err crond[20350]: crond (busybox 1.31.1) started, log level 8
Wed Dec 18 11:20:43 2019 daemon.warn pdnsd[20212]: Caught signal 15. Exiting.
Wed Dec 18 11:20:47 2019 cron.err crond[21429]: crond (busybox 1.31.1) started, log level 8
Wed Dec 18 11:20:50 2019 daemon.info pdnsd[21712]: pdnsd-1.2.9b-par starting.
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: Could not listen on tcp socket: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket
Wed Dec 18 11:20:50 2019 daemon.err pdnsd[21712]: error in UDP recv: Not a socket