where can i find build log?

i ever see the build log file,it includes all mk files, its name is “log”?? now i can not found it again.
how can i find it, or generate it?

Which build for which software? What command is used for the build?

it used TX2, i deleted the log, i am not sure how to build it.the log seems to build log.

Which build are you speaking of?