After implementing Facebook Login Auth with FBSDK, I tried to see / get the user in the Auth tab of Firebase Conh.
I take the fb credentials and pass them to FIRAuth, which has user arguments and errors. After printing, for the sake of visibility, an error certainly occurs, but I'm struggling to check it. I tried with breakpoints and got something similar to nonsense for me (I am new to Swift 2 days ago and coded 2 months ago).
Code: 
As you see above in the logs, has print("error above")been executed.
Error: 
Left - the result of the analysis of the breakpoint. This seems like nonsense to me and the people around me who looked at it :(
, print("credential above") . credential.description , FIRFacebookAuthCredential.
, Auth Facebook , Firebase Auth .
, , . Swift Firebase .
:
FBSDK Firebase.
Firebase docs, - Facebook Dev API, . , api, , , .
: , .
Edit
, ,
"Optional(Error Domain=FIRAuthErrorDomain Code=17999 \"An internal error has occurred, print and inspect the error details for more information.\" UserInfo={NSUnderlyingError=0x608000258c60 {Error Domain=FIRAuthInternalErrorDomain Code=3 \"(null)\" UserInfo={FIRAuthErrorUserInfoDeserializedResponseKey={\n code = 400;\n errors = (\n {\n domain = global;\n message = \"Unsuccessful debug_token response from Facebook: {\\\"error\\\":{\\\"message\\\":\\\"Invalid OAuth access token signature.\\\",\\\"type\\\":\\\"OAuthException\\\",\\\"code\\\":190,\\\"fbtrace_id\\\":\\\"FAA\\\\/****redacted****\\\"}}\";\n reason = invalid;\n }\n );\n message = \"Unsuccessful debug_token response from Facebook: {\\\"error\\\":{\\\"message\\\":\\\"Invalid OAuth access token signature.\\\",\\\"type\\\":\\\"OAuthException\\\",\\\"code\\\":190,\\\"fbtrace_id\\\":\\\"FAA\\\\/***redacted***\\\"}}\";\n}}}, error_name=ERROR_INTERNAL_ERROR, NSLocalizedDescription=An internal error has occurred, print and inspect the error details for more information.})"