There have been a number of posts in the past about Picard hanging/crashing when attempting to process a large number of files. Suggestions to address this have included breaking up the music files into smaller batches. I have been doing a lot of testing recently of my Classical Extras plugin, which has involved a fair number of writes to the log file. My observation is that Picard will hang if there are an excessive number of writes to the log file (in the order of hundreds of thousands). I have run the same code with and without the logging against the same file sets and it will hang if the logging is turned on and not hang if it is off. This behaviour has occurred identically with various versions of the code, log writes and file sets.
So maybe the cause of hanging with large numbers of files is nothing to do with the main Picard code, but merely a function of the number of log writes. Note that the total size of the log file seems to be irrelevant - it is the number of writes in the current session that seems to be critical.
Has anybody else noticed this? Perhaps someone could run an independent check of my hypothesis? Or better still, fix it?