The Linux ttyACM0 drama - more details after a lot of experimenting

Development Tools IDE 1.x
28

Hi, after some time I came back to this issue and I found I have problem just with ttyACM0 (Yun/Micro/etc. connected with microUSB cable) and ttyUSB0 (Uno connected with USB-B) is ok. But even this is interesting clue I can't figure it out.

I'm monitoring the rights on the tty devices:

watch -n 0.1 'ls -la /dev/ttyUSB* /dev/ttyACM*'
  • when uploading to ttyUSB0 just the date/time is changing and everything is working
  • when uploading to ttyACM0 device disappeared for a moment then a new one with wrong rights (and root:root) has been created, upload failed and then right are set properly by udev (with root:uucp) ... and then another one cycle (disappear-wrong-correct)

My user is in the lock and uucp groups, I've tried to add some udev rules or disable them but without success ...

I'm for 99% sure this is something before udev rule is touching it.