NFD

It seems that I fail to create an ipv6 face to a remote host. ( I have a successful ping6 to this host)
I have two different issues here:

First: failure when I use tcp6, not sure why -
can we add an explanation here? In this case, can we output the next error: Connect to remote endpoint failed: Invalid argument

$build/bin/nfdc create tcp6://[fe80::d6ae:52ff:fecd:260c]

ERROR: Face creation failed: Failed to create face

No errors in the nfd log, but this is the info output (I filtered out the DEBUG messages to get a shorter log here):

INFO: [FaceTable] addFace id=6
INFO: [ContentStore] insert() /localhost/nfd/faces/events/%04
INFO: [ContentStore] insertToSkipList() /localhost/nfd/faces/events/%04
INFO: [ContentStore] print()
INFO: [ContentStore] find() /localhost/nfd/faces/create/h%24r%22tcp6%3A%2F%2F%5Bfe80%3A%3Ad6ae%3A52ff%3Afecd%3A260c%5D/%00%00%01E%06%D9%8B2/Rj%C6%9F%F6%AB%3D%F9/%163%1B%01%01%1C.%07%2C%08%03tmp%08%04hila%08%03KEY%08%11ksk-1395870553073%08%07ID-CERT/%17%FD%01%006%87%605%25%FAx%DEJG.%EE%F8%C3%1D%D6%FC%DB%DE5%C6%E0U%10%F1%93%C0q%A4%C1i%BE%F4%A3%20%C19%1Fp%97%1B%A27IG%10M%A7G%B5%DEU%DC%BCa%88%E9%81%08%85c%D0%25A%12%80%AE%BE%B8%C0BW%23%04%8E%5DN%8Ec%BD%EC%99%90%FB%7C%D4%D1L%5EU%24bz%C3IP%F7%05D%7D%AD%BF%01%20%E1%A0%93m%A2%E7H%21%D8y%BA%0A%7F%C0%0F%A4%C8%04%1B%D1%B8PpJ%AD%7CWZz%83%A8%BB%D4z%0BH6%E6%93E%AC%7F%7Ed%05%E2%E9%BA%F8%11h%128%2C%C9%1F%B5H6%D3%A0V%B4%9D%0D%21%CC%83%91%AA%FBh%8Al%19%28%CF7W%27Ir%1C%5E%A7%8C%ABY%13%F2T%B1%03%A2%90%AA%D6%23%AA%F49%E2S%D1a%DD8J%15%8C%0E%A7%EFu%21%7E%BB%C9%3F%060%ED%A6y%D6%D6%AE%EBQTC7%D1%09dn%FC%E6%D6%F3%A8%08s%05%CB%5D%FB%ABZJ%7D%B8
INFO: [FaceManager] command result: processing verb: create
INFO: [FaceManager] Failed to create face: Connect to remote endpoint failed: Invalid argument
INFO: [ContentStore] insert() /localhost/nfd/faces/create/h%24r%22tcp6%3A%2F%2F%5Bfe80%3A%3Ad6ae%3A52ff%3Afecd%3A260c%5D/%00%00%01E%06%D9%8B2/Rj%C6%9F%F6%AB%3D%F9/%163%1B%01%01%1C.%07%2C%08%03tmp%08%04hila%08%03KEY%08%11ksk-1395870553073%08%07ID-CERT/%17%FD%01%006%87%605%25%FAx%DEJG.%EE%F8%C3%1D%D6%FC%DB%DE5%C6%E0U%10%F1%93%C0q%A4%C1i%BE%F4%A3%20%C19%1Fp%97%1B%A27IG%10M%A7G%B5%DEU%DC%BCa%88%E9%81%08%85c%D0%25A%12%80%AE%BE%B8%C0BW%23%04%8E%5DN%8Ec%BD%EC%99%90%FB%7C%D4%D1L%5EU%24bz%C3IP%F7%05D%7D%AD%BF%01%20%E1%A0%93m%A2%E7H%21%D8y%BA%0A%7F%C0%0F%A4%C8%04%1B%D1%B8PpJ%AD%7CWZz%83%A8%BB%D4z%0BH6%E6%93E%AC%7F%7Ed%05%E2%E9%BA%F8%11h%128%2C%C9%1F%B5H6%D3%A0V%B4%9D%0D%21%CC%83%91%AA%FBh%8Al%19%28%CF7W%27Ir%1C%5E%A7%8C%ABY%13%F2T%B1%03%A2%90%AA%D6%23%AA%F49%E2S%D1a%DD8J%15%8C%0E%A7%EFu%21%7E%BB%C9%3F%060%ED%A6y%D6%D6%AE%EBQTC7%D1%09dn%FC%E6%D6%F3%A8%08s%05%CB%5D%FB%ABZJ%7D%B8
INFO: [ContentStore] insertToSkipList() /localhost/nfd/faces/create/h%24r%22tcp6%3A%2F%2F%5Bfe80%3A%3Ad6ae%3A52ff%3Afecd%3A260c%5D/%00%00%01E%06%D9%8B2/Rj%C6%9F%F6%AB%3D%F9/%163%1B%01%01%1C.%07%2C%08%03tmp%08%04hila%08%03KEY%08%11ksk-1395870553073%08%07ID-CERT/%17%FD%01%006%87%605%25%FAx%DEJG.%EE%F8%C3%1D%D6%FC%DB%DE5%C6%E0U%10%F1%93%C0q%A4%C1i%BE%F4%A3%20%C19%1Fp%97%1B%A27IG%10M%A7G%B5%DEU%DC%BCa%88%E9%81%08%85c%D0%25A%12%80%AE%BE%B8%C0BW%23%04%8E%5DN%8Ec%BD%EC%99%90%FB%7C%D4%D1L%5EU%24bz%C3IP%F7%05D%7D%AD%BF%01%20%E1%A0%93m%A2%E7H%21%D8y%BA%0A%7F%C0%0F%A4%C8%04%1B%D1%B8PpJ%AD%7CWZz%83%A8%BB%D4z%0BH6%E6%93E%AC%7F%7Ed%05%E2%E9%BA%F8%11h%128%2C%C9%1F%B5H6%D3%A0V%B4%9D%0D%21%CC%83%91%AA%FBh%8Al%19%28%CF7W%27Ir%1C%5E%A7%8C%ABY%13%F2T%B1%03%A2%90%AA%D6%23%AA%F49%E2S%D1a%DD8J%15%8C%0E%A7%EFu%21%7E%BB%C9%3F%060%ED%A6y%D6%D6%AE%EBQTC7%D1%09dn%FC%E6%D6%F3%A8%08s%05%CB%5D%FB%ABZJ%7D%B8
INFO: [ContentStore] print()
INFO: [UnixStreamFace] [id:6,endpoint:/run/nfd.sock] Connection closed
INFO: [ContentStore] insert() /localhost/nfd/faces/events/%05
INFO: [ContentStore] insertToSkipList() /localhost/nfd/faces/events/%05
INFO: [ContentStore] print()
INFO: [FaceTable] removeFace id=6 

Second: When I use udp6, nfd crashes:

$build/bin/nfdc create udp6://[fe80::d6ae:52ff:fecd:260c] 

ERROR: error while receiving data from socket (End of file)

last nfd log lines:

DEBUG: [Forwarder] onOutgoingInterest face=1 interest=/localhost/nfd/faces/create/h%24r%22udp6%3A%2F%2F%5Bfe80%3A%3Ad6ae%3A52ff%3Afecd%3A260c%5D/%00%00%01E%06%D0%9AA/%F1%40%82%A8%9B%5C%D6O/%163%1B%01%01%1C.%07%2C%08%03tmp%08%04hila%08%03KEY%08%11ksk-1395870553073%08%07ID-CERT/%17%FD%01%00Yb%3B%93%B2%27t%00%A5+%1BLb%07%DC%B7%2A%06%29%18%F0%5E%85o%97%8CHK%A1%E3%ED%17%24%01%F5%ED%8A%D5%BBSj%F570%8BS%3DP7%96%CD%D1%8BB%B3X%0Dx%09%B0o%0D%80%BB%DD%B2i%AAg%81%1FA%83ZT%18%11b%3E_X%A6%DA%3C%B60%3E%26e%F0q%0D%C0%1B%FB%BE%D22%5D%8C%24f%EAr%F3%2FR%AA%0D%FD%8E%09g%B7%1DT%EE7%C7%B8%BC%92%1A%BCl%9C%EB%BDq%DC%06%10_%13%BE3D%81%EAB%8CS4%1B5%9E%07%C3%90%7Db0%E4j%16%ED%EE%D5%3Erw%03%E8%B4%EB%D1%DCu%9B%EAj%DD%E4%BF%AC%5D%23%81%DC%7Cx%DFS5%20%9C%0D%FB%CE%E8%82%285%F3%9D%C4%A2%87%2C%7BqCn%B9%0Am%05%5B%A1%0CX%88%01%1D%15%3F%18%F0%FB%B3%D8%C0%E3%90%1E%C0%E9%3E%3F%C1%ADHJxX%A6%12%D3%CC%D4G%C4e%E0%BD%9ExX%ECF%26%E6%B0KX%27
DEBUG: [InternalFace] received Interest: /localhost/nfd/faces/create/h%24r%22udp6%3A%2F%2F%5Bfe80%3A%3Ad6ae%3A52ff%3Afecd%3A260c%5D/%00%00%01E%06%D0%9AA/%F1%40%82%A8%9B%5C%D6O/%163%1B%01%01%1C.%07%2C%08%03tmp%08%04hila%08%03KEY%08%11ksk-1395870553073%08%07ID-CERT/%17%FD%01%00Yb%3B%93%B2%27t%00%A5+%1BLb%07%DC%B7%2A%06%29%18%F0%5E%85o%97%8CHK%A1%E3%ED%17%24%01%F5%ED%8A%D5%BBSj%F570%8BS%3DP7%96%CD%D1%8BB%B3X%0Dx%09%B0o%0D%80%BB%DD%B2i%AAg%81%1FA%83ZT%18%11b%3E_X%A6%DA%3C%B60%3E%26e%F0q%0D%C0%1B%FB%BE%D22%5D%8C%24f%EAr%F3%2FR%AA%0D%FD%8E%09g%B7%1DT%EE7%C7%B8%BC%92%1A%BCl%9C%EB%BDq%DC%06%10_%13%BE3D%81%EAB%8CS4%1B5%9E%07%C3%90%7Db0%E4j%16%ED%EE%D5%3Erw%03%E8%B4%EB%D1%DCu%9B%EAj%DD%E4%BF%AC%5D%23%81%DC%7Cx%DFS5%20%9C%0D%FB%CE%E8%82%285%F3%9D%C4%A2%87%2C%7BqCn%B9%0Am%05%5B%A1%0CX%88%01%1D%15%3F%18%F0%FB%B3%D8%C0%E3%90%1E%C0%E9%3E%3F%C1%ADHJxX%A6%12%D3%CC%D4G%C4e%E0%BD%9ExX%ECF%26%E6%B0KX%27
DEBUG: [InternalFace] found Interest filter for /localhost/nfd/faces (previous match)
DEBUG: [ManagerBase] Parameters parsed OK
INFO: [FaceManager] command result: processing verb: create
DEBUG: [FaceUri] URI [udp6://[fe80::d6ae:52ff:fecd:260c]] parsed into: udp6, fe80::d6ae:52ff:fecd:260c, , 
ERROR: [Main] Error: Failed to properly configure the socket. Check the address (connect: Invalid argument)