Late on the 28th it sadly came to my attention that some users were experiencing severe problems with their printer communication after upgrading to the 1.2.14 release just published earlier that day. I immediately stopped the roll out of 1.2.14 and went to investigate.

Since I couldn’t reproduce the issue myself, I had to depend on affected users to help in determining the cause of the problems.

Yesterday morning we narrowed in on a single commit introducing the behaviour and a fix I pushed shortly after solved the problem for everyone who so far reported back. I decided on having people test this fix until today to make sure it really was the reason for the communication issues.

At this point, let me extend a big big “Thank You!” to everyone who helped identifying the cause of the problem and verifying the fix!

On top of those issues, users depending on the GPX and the M33 Fio plugins were also running into problems caused by a compatibility issue between the serial wrappers in these plugins and 1.2.14. I took the opportunity to also add a workaround to OctoPrint detecting that incompatibility and wiggling around it. Both plugins have since also been updated though.

Two other minor issues reported after the release of 1.2.14 were also fixed.

So, how do we prevent something like this from happening again?

Sadly no matter how many days I invest into testing new releases against actual printers, it is impossible to test all potential combinations considering that they are pretty much endless. Things like the above may slip through simply because they do not reproduce for me, be it because I have the wrong printer, the wrong controller, the wrong firmware, the wrong firmware configuration or EEPROM settings, a slightly slower or faster testing machine or just more luck.

But apparently you, OctoPrint’s users, are very good at covering every single possible hardware/software/usage scenario combination under the sun! So let’s try something new. I’ll set up an opt-in beta program and will put new releases through that first - let’s say, a week before full release. That will give a wider audience easy access to upcoming releases and increase the likelihood of catching issues like the above before they are rolled out to everyone, with direct help if problems are encountered to get things going again, and of course with the goal to find and implement a general solution.

Also, to make sure you always know how to roll back to an earlier version, this and all future release announcements will also include explicit links to the roll back instructions on the wiki - see “Links” below. I’ll also think about some tool support to make rolling back even easier.

For now though, here’s 1.2.15, the better 1.2.14.

You can find the full changelog and release notes as usual on Github.

Further Information

It may take up to 24h for your update notification to pop up, so don’t be alarmed if it doesn’t show up immediately after reading this. You can force the update however via Settings > Software Update > Advanced options > Force check for update.

If you don’t get an “Update Now” button with your update notification, read this or - even more specifically - this.

If you do get an “Update Now” button but the update is immediately reported to be successful without any changes, read this.

If you have any problems with your OctoPrint installation, please seek support in the G+ Community or the Mailinglist.

Gina Häußge
30 Jul 2016