Merging plugin configuration from profile

Question

I have a configuration entry for exec-maven-plugin

                    <configuration>
                        <executable>compass</executable>
                        <arguments>
                            <argument>compile</argument>
                            <argument>-c</argument>
                            <argument>config_production.rb</argument>
                            <argument>--force</argument>
                        </arguments>
                    </configuration>

now in the profile I would like to combine this configuration with:

                                <configuration>
                                    <arguments>
                                        <argument>compile</argument>
                                    </arguments>
                                </configuration>

because combine.children="merge"by default, I expect the effective configuration to be:

                    <configuration>
                        <executable>compass</executable>
                        <arguments>
                            <argument>compile</argument>
                        </arguments>
                    </configuration>

but instead, it matches the original.

What gives? I tried the installation combine.children="merge"and to combine.self="override"no avail.

The Maven documentation mentions “how child POMs inherit configuration from parent POMs,” but I expect merging with profiles to work the same.

The above results show that merging with profiles works differently - how?