Teensy 3.5 doesn't become programmed

[jwatte]

I have a Teensy 3.5, connected to an Ubuntu 17.04 x64 machine.
I'm using Arduino 1.8.4 and a recent Teensyduino (forget the exact version.)
This Teensy has been programming just fine; I've loaded some audio sketches on it before.

Today, when I try to program it, the programmer doesn't actually "see" it. The gray window with blue progress bar that overlays the picture of the Teensy doesn't show up.
This is even if I press the button on the board.

Here's what I see in dmesg when I plug it in:

[ 1200.231012] usb 1-3: new full-speed USB device number 7 using xhci_hcd
[ 1200.532041] usb 1-3: New USB device found, idVendor=16c0, idProduct=04d2
[ 1200.532043] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1200.532045] usb 1-3: Product: Teensy Audio
[ 1200.532046] usb 1-3: Manufacturer: Teensyduino
[ 1200.532047] usb 1-3: SerialNumber: 2580010
[ 1200.546838] hid-generic 0003:16C0:04D2.0009: hidraw5: USB HID v1.11 Device [Teensyduino Teensy Audio] on usb-0000:01:00.0-3/input0
[ 1200.588795] usb 1-3: Warning! Unlikely big volume range (=4095), cval->res is probably wrong.
[ 1200.588798] usb 1-3: [49] FU [PCM Playback Volume] ch = 2, val = 0/4095/1

It's running the old sketch, which is a USB audio device.

Here's what I see when I press the programming button:

[ 1214.846419] usb 1-3: USB disconnect, device number 7

That's it. Nothing more. Here's the device in lsusb:

[18:51] jwatte@ripper:~$ lsusb
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 003: ID 1a2c:2e43 China Resource Semico Co., Ltd 
Bus 007 Device 002: ID 258a:1007  
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 1b1c:0c0a Corsair 
Bus 001 Device 008: ID 16c0:04d2 Van Ooijen Technische Informatica 
Bus 001 Device 003: ID 1b1c:1c0c Corsair 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

And it goes away after I press the programming button:

[18:51] jwatte@ripper:~$ lsusb
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 003: ID 1a2c:2e43 China Resource Semico Co., Ltd 
Bus 007 Device 002: ID 258a:1007  
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 1b1c:0c0a Corsair 
Bus 001 Device 003: ID 1b1c:1c0c Corsair 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

What's going on? What can I try to do to recover this board?
(This board was one of the Kickstarter reward boards, if that matters.)

 

[KurtE]

Did you try the hold program button for 15 seconds, to see if it would reset it. Needs to be close to 15, like I think >13 <17.

Also sometimes I have luck by plugging in board while holding program button

 

[jwatte]

I took the board to a Windows machine, and it could be programmed with Blink just fine there.
After plugging it back into the Linux machine, it could be programmed once (using IDE -> auto-upload) and then not programmed again.
Until I took it back to the Windows machine and Blink-ed it again.
My guess is that the Ubuntu 17.04 USB stack has suffered some ... mutation? In a recent update?