When Joiners fail they output the following in the logfile:
2017-05-16 10:42:17| 53.6| 0.0|ERROR |BADNEWS: 0 matches were found in the table used by relation `Joiner_4' (which is supposed to be 1-1) -- key values were: X== `' (relation.cpp:694) 2017-05-16 10:42:17| 53.6| 0.0|ERROR |0 matches were found in the table used by relation `Joiner_4' (which is supposed to be 1-1) -- key values were: XXX== `' 2017-05-16 10:42:17| 53.6| 0.0|ERROR |(featproci.cpp:701) - (cmrelate.cpp:227) - (relation.cpp:694) 2017-05-16 10:42:17| 53.6| 0.0|ERROR |BADNEWS: A fatal error has occurred. Check the logfile above for details (dynafact.cpp:315)
Also write the complete feature that failed in the logfile (similar to putting it through a Logger) for instance:
2017-05-16 10:42:17| 53.4| 0.0|INFORM|=========================================================================== 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Joiner_4 - Logg failed feature: 2017-05-16 10:42:17| 53.4| 0.0|INFORM|+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Feature Type: `Joiner_4_Logger' 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Attribute(32 bit integer) : `x' has value `1' 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Attribute(string) : `y' has value `fads.fds.fsad.fdsafdsa' 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Attribute(32 bit integer) : `z' has value `fasfasd' 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Attribute(32 bit integer) : `asdf' has value `ffasdfsda' 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Attribute(string) : `134' has value `234234' 2017-05-16 10:42:17| 53.4| 0.0|INFORM|Attribute(string) : `fasdf' has value `32434'


