Hello, I promize you another question related to my sbuild property 
So this property generate at the end a chroot in a file
/var/lib/sbuild/jessie-i386.tar.gz
Since this process take a lot's of time, I do not want to run this process each time. I would like to process this property only if the file does not exists.
I found the flagFile property but I do not think that it is the right answer to my problem.
I just want to express that a file is the result of a property and no need to re-run the proerty if this file exists.
Cheers
My suggestion in the specific case of the sbuild property would be to generate the file whenever the property that generates the chroot has to make a change. The
onChangecombinator accomplishes that.But if you really want to only run the property if the file doesn't exist, you can do that by using the
checkcombinator. For example: