Problem of crashing command on "lightningd/lightningd --network=testnet --log-level=debug" When I try running the "lightningd/lightningd --network=testnet --log-level=debug" after sucessfully starting the Bitcoin server using the "bitcoind -daemon -testnet" ,following issue occurs:

lightningd/lightningd --network=testnet --log-level=debug
2018-02-12T12:34:40.313Z lightningd(14966): Trying to guess public addresses...
2018-02-12T12:34:40.313Z lightningd(14966): Address 192.168.0.73:9735 is not routable
2018-02-12T12:34:40.313Z lightningd(14966): Failed to connect 10 socket: Network is unreachable
2018-02-12T12:34:40.313Z lightningd(14966): testing /home/blockchain/lightning/lightningd/lightning_channeld
2018-02-12T12:34:40.314Z lightningd(14966): testing /home/blockchain/lightning/lightningd/lightning_closingd
2018-02-12T12:34:40.314Z lightningd(14966): testing /home/blockchain/lightning/lightningd/lightning_gossipd
2018-02-12T12:34:40.315Z lightningd(14966): testing /home/blockchain/lightning/lightningd/lightning_hsmd
2018-02-12T12:34:40.315Z lightningd(14966): testing /home/blockchain/lightning/lightningd/lightning_onchaind
2018-02-12T12:34:40.316Z lightningd(14966): testing /home/blockchain/lightning/lightningd/lightning_openingd
2018-02-12T12:34:40.471Z lightningd(14966): Client: Received message 11 from client
2018-02-12T12:34:40.480Z lightningd(14966): Loaded 0 invoices from DB
2018-02-12T12:34:40.480Z lightningd(14966): Client: Received message 9 from client
2018-02-12T12:34:40.480Z lightning_gossipd(14974): pid 14974, msgfd 12
2018-02-12T12:34:40.481Z lightningd(14966): Loaded 0 channels from DB
bitcoin-cli exited with code 1: error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file (/home/lightning/.bitcoin/bitcoin.conf)

2018-02-12T12:34:40.518Z lightningd(14966): bitcoin-cli exited with code 1: error: Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file (/home/lightning/.bitcoin/bitcoin.conf)

Log dumped in crash.log
2018-02-12T12:34:40.545Z lightningd(14966): FATAL SIGNAL 6 RECEIVED
2018-02-12T12:34:40.548Z lightningd(14966): backtrace: lightningd/log.c:486 (log_crash) 0x410b18
2018-02-12T12:34:40.561Z lightningd(14966): backtrace: (null):0 ((null)) 0x7fc0b7dc24af
2018-02-12T12:34:40.561Z lightningd(14966): backtrace: (null):0 ((null)) 0x7fc0b7dc2428
2018-02-12T12:34:40.561Z lightningd(14966): backtrace: (null):0 ((null)) 0x7fc0b7dc4029
2018-02-12T12:34:40.561Z lightningd(14966): backtrace: lightningd/log.c:575 (fatal) 0x410f52
2018-02-12T12:34:40.561Z lightningd(14966): backtrace: lightningd/bitcoind.c:723 (wait_for_bitcoind) 0x4056c9
2018-02-12T12:34:40.562Z lightningd(14966): backtrace: lightningd/chaintopology.c:723 (setup_topology) 0x407bd8
2018-02-12T12:34:40.562Z lightningd(14966): backtrace: lightningd/lightningd.c:331 (main) 0x40f258
2018-02-12T12:34:40.562Z lightningd(14966): backtrace: (null):0 ((null)) 0x7fc0b7dad82f
2018-02-12T12:34:40.562Z lightningd(14966): backtrace: (null):0 ((null)) 0x403248
2018-02-12T12:34:40.562Z lightningd(14966): backtrace: (null):0 ((null)) 0xffffffffffffffff
Fatal signal 6. 0x410bfe log_crash
    lightningd/log.c:512
0x7fc0b7dc24af ???
    ???:0
0x7fc0b7dc2428 ???
    ???:0
0x7fc0b7dc4029 ???
    ???:0
0x410f52 fatal
    lightningd/log.c:575
0x4056c9 wait_for_bitcoind
    lightningd/bitcoind.c:723
0x407bd8 setup_topology
    lightningd/chaintopology.c:723
0x40f258 main
    lightningd/lightningd.c:331
0x7fc0b7dad82f ???
    ???:0
0x403248 ???
    ???:0
0xffffffffffffffff ???
    ???:0
Log dumped in crash.log
Aborted (core dumped)

Can anybody please solve my issue and explain me what is exactly happening!
The issue seems to be contained in the error message. 

Could not locate RPC credentials. No authentication cookie could be found, and no rpcpassword is set in the configuration file (/home/lightning/.bitcoin/bitcoin.conf)


So, set rpcuser and rpcpassword appropriately in ~/.bitcoin/bitcoin.conf.