Logs

Top-level build scripts print only the progress of the build. Actual log lines are redirected to the build.log file. It is the first file to look if you encounter an error.

On some occasions, if the details inside build.log are not enough to understand the root cause of the failure, you will need to look inside configuration log file (config.log) of library compiled at that moment; which will have a path like src/LIBRARY/config.log. For ffmpeg this file is located under src/ffmpeg/ffbuild folder.