Serial REPL/ USB CDC issue on OS X 10.10.5

[siddacious]

I’ve been testing 3.0/master on a M4 with my early 2015 MacBook Pro 13 Retina running Yosemite. My M4 bootloader was flashed with BOSSAC with a .bin provided by @tannewt.

Here’s what I’m seeing with the current master and a build @tannewt sent last night around 9pm:

• No /dev/tty.usbmodem* when the M4 is plugged in
• CIRCUITPY mounts and is accessible
• a code.py blinky in CIRCUITPY will run when written or reset
• removing code.py or any .py in CIRCUITPY and resetting/powercycling several times does not change the CDC issue

I tested multiple different usb ports:

• two internal 3.0
• 3.0 on thunderbolt hub
• 2.0 on thunderbolt hub

I've also tested with and without the DC jack on the metro

At @tannewt’s suggestion, I found the following in dmesg:

USBMSC Identifier (non-unique): 0x239a 0x8021 0x100
       0        0 AppleUSBCDCACMControl: getFunctionalDescriptors - Descriptors are incorrect, checking...
       0        1 AppleUSBCDCACMData: start - Find CDC driver for ACM data interface failed
       0        1 AppleUSBCDCECMData: start - Find CDC driver for ECM data interface failed
AppleUSBCDC: Version number - 4.3.2b1
Google Chrome He (map: 0xffffff80329241e0) triggered DYLD shared region unnest for map: 0xffffff80329241e0, region 0x7fff89200000->0x7fff89400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
USB (XHCI Root Hub USB 2.0 Simulation):Port 1 on bus 0xa connected or disconnected: portSC(0xe0206e1)
USBMSC Identifier (non-unique): 0x239a 0x13 0x4201
         0 [Level 5] [com.apple.message.domain com.apple.commssw.cdc.device] [com.apple.message.signature AppleUSBCDCACMData] [com.apple.message.signature2 0x239A] [com.apple.message.signature3 0x13]
AppleUSBCDCACMData: Version number - 4.3.2b1, Input buffers 8, Output buffers 16
AppleUSBCDC: Version number - 4.3.2b1