ERROR: Unexpected character 'M' found

[dingyigithub]

Hello! Thanks for developing such an amazing tool. However when I apply the IGDA to my mitochondria bam file , it throws an error.
Here are details:
I am running igda_pipe_detect and the parameters are all default.
After it starts the "getbamchrrange" step, there is an error: "ERROR: Unexpected character 'M' found."
I wonder if there is some solution to fix it? like slightly correct my alignment chromosome information 'chrM' or add some code so it can identify the chrM.
Thank you very much!