Logback 1.6.2

clean.full.1.6.2.mp4

2026-08-10 Release of logback version 1.6.2

• Configuration analysis now detects contradictory caller-data inclusion instructions. For example, an AsyncAppender, SocketAppender or SMTPAppender with includeCallerData left at the default false is incompatible with a layout or encoder pattern that uses a caller-data converter such as %C, %M, %L, %F, %l or %caller. At runtime those converters would print question marks and still incur extraction cost on a worker thread. Logback now emits a configuration-time warning when such instructions disagree. See codes.html#callerContradiction for details. This issue was reported in issues/1059 by leeychee. The initial analysis was contributed by seonwoo_jung.

• Caller-contradiction analysis can be turned off by setting the logback.skipCallerContradictionAnalysis variable to true, either as a system property (-Dlogback.skipCallerContradictionAnalysis=true) or as a property in the configuration file:

  <property name="logback.skipCallerContradictionAnalysis" value="true"/>

• SimpleSocketServer and SimpleSSLSocketServer now require an explicit client IP whitelist. On the command line, pass one or more allowed addresses (single IPs or CIDR ranges) after the configuration file. An empty whitelist means no clients are accepted. When embedding the server programmatically, register allowed addresses with addAllowedClientAddress(String) or setAllowedClientAddresses(Collection) before clients connect. See the documentation on restricting client access.

• Added ThrowableProxyVOBuilder for assembling a ThrowableProxyVO field by field, with a corresponding ThrowableProxyVO.builder() entry point.

• Dependency analysis handlers now run their postHandle method after child models have been processed, so checks that depend on nested appenders (such as caller-contradiction analysis) see a complete picture.

• Updated several dependencies, including Angus Mail to 2.0.4 and Jetty (test) to 12.1.12.

• A bit-wise identical binary of this version can be reproduced by building from source code at commit e3d7833 associated with the tag v_1.6.2. The release was built using Java "21" 2023-10-17 LTS build 21.0.1.+12-LTS-29 under Linux Debian 11.6.