$ # s6 = s3 + spring-boot-properties-migrator (runtime scope)
[INFO] BUILD SUCCESS
app started
$ grep -iE 'propert|logging.file|migrat' run.log   # what the migrator printed at start-up
WARN 6819 --- [           main] o.s.b.c.p.m.PropertiesMigrationListener  : 
The use of configuration keys that have been renamed was found in the environment:
Property source 'Config resource 'class path resource [application.properties]' via location 'optional:classpath:/'':
	Key: logging.file.max-history
		Replacement: logging.logback.rollingpolicy.max-history
	Key: logging.file.max-size
		Replacement: logging.logback.rollingpolicy.max-file-size
Each configuration key has been temporarily mapped to its replacement for your convenience. To silence this warning, please update your configuration to use the new keys.
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