The Stack Overflow

For some reason my mod broke and started crashing during startup, and it did so in the worst possible way - without any error message! All I got in the Intellij Idea, was a message that the process exited with the signal code 11. WHAT?
That signal corresponds to SIGSEGV signal on Linux, which generally means you did something wrong with the memory. But this is Rust! There shouldn’t be any memory issues!
I started searching, and I learned there is a tool called coredumpctl, which lets me access a special dump file generated in such cases, and analyze it in a debugger like GDB. So I did that, and what I found was even more bizzare! The debugger was pointing to a start of a function, before the first line. I added some debug prints, and to my disbelief, the print before calling that function ran, and the the second one, which was the first line inside the function didn’t!
Fast forward a bit I managed to figure out the problem, with some help from a friend. It turned out I encountered an stack overflow! When the function was called, Rust tried to expand the stack, and crashed because the stack ran out!
Why?
Because the code was loaded in Java, and Java by default allocates less memory for the stack!
The solution was manually requesting a bigger stack size during thread creation in Java.
I also discovered, why the problem appeared - in the Rust file download code I had allocated an array buffer of 1MB. It landed on the stack, and that was too much! The solution was using a Vec, which lives on the heap instead.
Stupid problem, but took 3 hours of my time 😩

Mod init progress reporting

Sephyr requires the IPA speech recognition model to work, which needs to be downloaded on the first run, and subsequently loaded from the disk. The logic was overhauled providing more corectness, and hooked up to a series of toasts. File download progress bar is shown, and the intialization state (or failure) is coummunicated to the user!
See it in the video