pom.xml:

            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <image>
                        <env>
                            <FOO></FOO>
                        </env>
                    </image>
                </configuration>
            </plugin>

result:

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.4.0-SNAPSHOT:build-image (default-cli) on project func: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.4.0-SNAPSHOT:build-image failed: String must not be null -> [Help 1]

Comment From: scottfrederick

@dsyer What are you expecting to happen with your use case - should the empty env entry be ignored or should an entry named FOO be provided to the builder with an empty value? The latter seems appropriate, but I'm wondering if there's something specific that led you to try this.

Comment From: dsyer

The value is empty so null is a poor representation I would say. Your call. I stumbled on this accidentally, but I wild t expect it to blow up really.