Log exceptions when a demo fails to parse

[MarkKoz]

Currently the app just says a demo failed to parse. More detail is needed when debugging. Currently, the app has to be manually edited to add a line to log the exception. It'd be more convenient if the exception was retrievable from the production environment, especially if the cause is difficult to reproduce. Logging exceptions to stdout may not be user-friendly. If we care about that, then it can be written to a log file.

[MarkKoz]

On the refactor branch, it doesn't seem possible to log to stdout in conjunction with the progress bar library being used. The library does support writing messages above the progress bars, but it seems to only render those messages until the next screen update is called. From my very brief investigation of it, writing such messages pushes to a queue and consumes it when rendering the messages.

Ideally, the log messages would be written in real time above the progress bar, and the progress bar would essentially be pinned to the bottom. In such case, having a bar remain for each demo could become quite cluttered with large batches, so a single progress bar would likely be best. Anyway, there doesn't seem to be a simple way to accomplish that with the current library. I haven't seen any existing alternatives either.

I'm currently considering saving all the log messages and writing them to stdout after the progress bar. Not sure if this will work or if the progress bar would still interfere after it's done being updated. The concern is that this could use a lot of memory if the volume of logs is high, but I don't anticipate this in the typical use case. A solution I can quickly think of for that is to write the logs to a file and then read and dump it to stdout at the end.

As a longer term goal, I think supporting something like ILogger at the library level would be nice. There's currently no introspection into what the parser, collector, or processor is doing at a given moment.