How to use swiftlint analyze? And `swiftlint analyze` reports extra warnings beyond `analyzer_rules` configuration.

Problem

In my .swiftlint.yml file, I only set the analyzer rule:

analyzer_rules:
- explicit_self

I run code analysis with the following commands:

xcodebuild -workspace XXX.xcworkspace \
                    -scheme XXX \
                    -destination 'id=CF68E389-C815-4918-B133-BE4839938B6F' \
                    clean build | tee xcodebuild-build.log

swiftlint analyze --compiler-log-path xcodebuild-build.log

However, the results contain not only explicit_self issues, but also other warnings such as:

value was defined but never used

These extra warnings seem to come from the Xcode build result itself, but I expected swiftlint analyze to only report issues from analyzer_rules.

Question

1. How can I make swiftlint analyze report only issues defined in analyzer_rules?
2. Are there more examples or best practices for using swiftlint analyze? Documentation is very limited.

Start with the documented swiftlint analyze --compiler-log-path workflow and the .swiftlint.yml analyzer_rules configuration described in the issue. Clarify how build-log warnings relate to configured analyzer rules, then add usage examples and best practices; done means the two questions are answered in the documentation.