Arduino Web Editor - Fatal Error - bytecode stream generated with LTO version 3.

Good day all

I last used my web editor a few months ago and now it is generating an error message when I click the verify button.

This is happening for all sketches, even from the Editor’s Examples.

I have tried…

  1. Rebooting my machine
  2. Searching on google for the specific error.
  3. Uninstalling and re-installing the Arduino Bridge.

None of these have resolved the issue. Can someone with more experience please help?

Error reads as follows…

lto1: fatal error: bytecode stream generated with LTO version 3.0 instead of the expected 4.1

compilation terminated.

lto-wrapper: fatal error: ./opt/tools/avr-gcc/5.4.0-atmel3.6.1-arduino2/bin/avr-gcc returned 1 exit status

compilation terminated.

/home/ubuntu/opt/tools/avr-gcc/5.4.0-atmel3.6.1-arduino2/bin/…/lib/gcc/avr/5.4.0/…/…/…/…/avr/bin/ld: error: lto-wrapper failed

collect2: error: ld returned 1 exit status

exit status 1

There are multiple other reports of this bug:

I recommend subscribing to those threads so that you'll be sure to get news of any progress in fixing it.

This is an Arduino Web Editor specific problem so the workaround is to use the regular Arduino IDE, which you can download for free from:

FYI, this is not the correct forum section to report problems with the Arduino Web Editor. This is the place for discussion about the Arduino Project Hub, which is a different thing. The Arduino Web Editor section is here: I have already requested that this thread be moved there so no need to create a duplicate post.

Hello, please follow topic Issue 2018-10-30: lto-wrapper error prevent compilations for further information and updates about this.

Thank you.