It is impossible to have a (complex) build command before the defaults.

For a project using an external tool builder it is impossible to have it run BEFORE the defaults (like javabuilder). Or I didn't find an intuitive way to do it, correct me if I'm wrong. The builder in question is, for example, an invocation of ANT (which generates additional code to be compiled by javac):

<additionalBuildcommands>
<buildCommand>
<name>org.ui.externaltools.ExternalToolBuilder</name>
<triggers>auto,full,</triggers>
<arguments>
<LaunchConfigHandle><project>/.externalToolBuilders/xxx.launch</LaunchConfigHandle>
</arguments>
</buildCommand>
</additionalBuildcommands>

Any builders from additionalBuildcommands are appended to the list after the defaults. None of the following solve the problem:

• adding javabuilder to <additionalBuildcommands> (after external builder),
• specifying an empty <buildcommands></buildcommands> element to force no-defaults (this would be my expectation to have a custom ordering of build commands in additionalBuildcommands, but no – no luck),
• specifying external tool builder in <buildcommands> is impossible because it takes arguments.

Any other cues?