Regarding the crash: Given this is a null pointer dereference: Can you check whether the serial port is opened by the program in the first place, e.g. using lsof?
Do the control functions (USB host/target switch, etc.) work before changing the baudrate? For me, it crashes as well with no hardware attached... Also, there have been 19 commits upstream since 0.1.0 and the commit messages are very confusing. I will try a local build of current upstream main and check whether it crashes as well. -- ceterum censeo microsoftem esse delendam.
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