Exclude logback-classic from bio-formats_plugins

It is really an optional dependency; the library works without it.

Author: ctrueden

pom.xml

@@ -3488,6 +3488,31 @@
 				<groupId>ome</groupId>
 				<artifactId>bio-formats_plugins</artifactId>
 				<version>${ome.bio-formats_plugins.version}</version>
+				<exclusions>
+					<exclusion>
+						<!--
+						The banDuplicateClasses rule of the maven-enforcer-plugin reports a
+						conflict between logback-classic & slf4j-simple in some scenarios.
+						Both include an SLF4J binding (org.slf4j.impl.StaticLoggerBinder).
+						Perhaps the classpath of the tooling also includes slf4j-simple?
+						Regardless, it is generally problematic to inflict a specific SLF4J
+						binding on downstream consumers. "Embedded components such as
+						libraries or frameworks should not declare a dependency on any
+						SLF4J binding but only depend on slf4j-api."
+						See: https://www.slf4j.org/manual.html#libraries
+
+						In any case: the bio-formats_plugins usage of logback-classic is
+						limited to the class loci.plugins.util.IJStatusEchoer, accessed
+						only via reflection from ome-common's loci.common.DebugTools class,
+						with the intent that this dependency may or may not actually be
+						present at runtime. So this dependency really should be marked
+						optional in the bio-formats_plugins POM, but since it is not
+						marked so, we exclude it here in pom-scijava instead.
+						-->
+						<groupId>ch.qos.logback</groupId>
+						<artifactId>logback-classic</artifactId>
+					</exclusion>
+				</exclusions>
 			</dependency>
 			<dependency>
 				<groupId>ome</groupId>