How to program a BSFrance LoRA32u4 from Arduine IDE 8.5? I've bought a BSFrance LoRA32u4 from DIYmall on eBay UK.

https://bsfrance.fr/lora-long-range/1311-BSFrance-LoRa32u4-1KM-Long-Range-Board-Based-Atmega32u4-433MHz-LoRA-RA02-Module.html

I've copied the "bsfrance" directory (from the ZIP) into Arduino/hardware (on 64-bit Ubuntu 16.04).

Staring the Arduino IDE, I've selected the correct board (Tools>>Board>>BSFrance>>LoRA32u4).

I've selected the correct port Tools>>Port>>/dev/ttyACM1 (LoRA32u4).

Verifying a trivial sketch looks fine:

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}


Result:

Sketch uses 4104 bytes (14%) of program storage space. Maximum is 28672 bytes.
Global variables use 149 bytes of dynamic memory.


The USB device appears in lsusb as: Bus 002 Device 077: ID 239a:800c.

Clicking install causes a white LED to flicker for around ten seconds, but results in:

avrdude: error: buffered memory access not supported. Maybe it isn't
a butterfly/AVR109 but a AVR910 device?
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.


or:

Couldn't find a Board on the selected port. Check that you have the
correct port selected.  If it is correct, try pressing the board's reset 
button after initiating the upload.


or:

Found programmer: Id = "CATERIN"; type = 


or:

Device code: 0x0d


or:

.   Software Version = 1.0; Hardware Version = 


or:

An error occurred while uploading the sketch


How do I transfer code onto this board?

(I am new to Arduino, so I may be missing something obvious.  I do have lots of experience programming vanilla ATMEGAs in C without the Arduino IDE.)

--

I have an AVRISP mkII - would burning a new boot-loader help, or just wreck the USB-serial on the device?
I've had the same problem, but couldn't fix it with the "Upload using programmer".
Instead i sound that the problem was that the serial connection kept dropping after a couple of seconds. My colleague, also on Ubuntu, had the same issue.

This fixed it for me: https://learn.adafruit.com/adafruit-arduino-ide-setup/linux-setup#udev-rules

The board registers as an Adafruit board on my system, and apparently the ModemManager is not too keen on that. 

After running first command in the link and restarting, i could upload to the board from Arduino IDE with no errors.