After upgrading to Spring Boot v4.0.0-M3 the console log messages have a big empty gap before the package name, e.g.

2025-09-29T14:39:16.092Z  INFO 75130 --- [MyApp] [  restartedMain] [                                                 ] com.example.package    : Starting BidsEngineApplication using Java 25 with PID 75130
2025-09-29T14:39:16.093Z DEBUG 75130 --- [MyApp] [  restartedMain] [                                                 ] com.example.package    : Running with Spring Boot v4.0.0-M3, Spring v7.0.0-M9
2025-09-29T14:39:16.093Z  INFO 75130 --- [MyApp] [  restartedMain] [                                                 ] com.example.package    : The following 1 profile is active: "local"

Previously, my app didn't specify any custom log patterns either in the Spring config files or in a logging (Logback) config file.

I resolved this, by adding the patterns below to the Spring config, which I copied from Spring Boot and replaced :- with :

logging:
  level:
    root: INFO
    web: DEBUG
  pattern:
    console: "${CONSOLE_LOG_PATTERN:%clr(%d{${LOG_DATEFORMAT_PATTERN:yyyy-MM-dd'T'HH:mm:ss.SSSXXX}}){faint} %clr(${LOG_LEVEL_PATTERN:%5p}){} %clr(${PID:}){magenta} %clr(--- %esb(){APPLICATION_NAME}%esb{APPLICATION_GROUP}[%15.15t] ${LOG_CORRELATION_PATTERN:}){faint}%clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:%wEx}}"
    file: "${FILE_LOG_PATTERN:%d{${LOG_DATEFORMAT_PATTERN:yyyy-MM-dd'T'HH:mm:ss.SSSXXX}} ${LOG_LEVEL_PATTERN:%5p} ${PID:} --- %esb(){APPLICATION_NAME}%esb{APPLICATION_GROUP}[%t] ${LOG_CORRELATION_PATTERN:}%-40.40logger{39} : %m%n${LOG_EXCEPTION_CONVERSION_WORD:%wEx}}"

Comment From: wilkinsona

This is to be expected when Micrometer Tracing is on the classpath. It is for the logging of correlation IDs. The log messages shown above have no correlation ID, hence the gap. If you're seeing the gap without Micrometer Tracing on the classpath, or you never see a correlation ID even when there should be one, please provide a minimal sample that reproduces the problem and we can re-open the issue and take another look.