Build properties are a generalized way to provide configuration information to build steps; see Build Properties.
Some build properties are inherited from external sources – global
properties, schedulers, or buildslaves. Some build properties are
set when the build starts, such as the SourceStamp information. Other
properties can be set by BuildSteps as they run, for example the
various Source steps will set the
got_revision property to the
source revision that was actually checked out (which can be useful
when the SourceStamp in use merely requested the “latest revision”:
got_revision will tell you what was actually built).
In custom BuildSteps, you can get and set the build properties with
setProperty methods. Each takes a string
for the name of the property, and returns or accepts an
arbitrary1 object. For example:
class MakeTarball(ShellCommand): def start(self): if self.getProperty("os") == "win": self.setCommand([ ... ]) # windows-only command else: self.setCommand([ ... ]) # equivalent for other systems ShellCommand.start(self)
 Build properties are serialized along with the build results, so they must be serializable. For this reason, the value of any build property should be simple inert data: strings, numbers, lists, tuples, and dictionaries. They should not contain class instances.