Collision found when developing extensions


I’ve been developing a bit an extension and would like to change the boolean properties of a class from select to checkbox. This is a replacement of a class and I am meeting a strange error when I try to install the extension:

  • the xar is made of the XML I extracted from the wiki. There, the object instance contains an actualised copy of the class (as is normal with classes, right?)
  • importing the xar with the content import works ok
  • importing the xar through the extension install from my maven repository shows me a collision Collision found on property [xxx] between from value [0] and to [0]

Here are my questions:

  • how can I debug this?
  • is there any reason for me to include the class in XML of the object? Does it not make sense to avoid that so that such conflicts are avoided?



The first thing to do when you have a conflict is using the conflict UI to compare previous vs current, current vs new, previous vs new to understand what made the 3 ways merge hit a conflict.

Hold on, a conflict of 3-way merge is something I understand well.
Is a collision the same as a conflict but for properties?

What is called a “collision” here is the result of a 3 ways merge conflict yes. The value of this property was apparently different between the previous standard version and the version in database and it’s been changed in the new standard version.