bach clean build doesn't rebuild module bach.info

[sormuras]

bach clean build
Bach 17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z (Java 16+36-2231, Windows 10, D:\dev\github\sormuras\bach)
Build bach 17-custom+20210325103746
Verify external modules located in file:///D:/dev/github/sormuras/bach/.bach/external-modules/
Verified 11 external modules
Build 1 main module: com.github.sormuras.bach
  javac    --release 16 --module com.github.sormuras.bach --module-version 17-custom+20210325103746 --module-source-path .\[...]
  jar      --create --file .bach\workspace\modules\com.github.sormuras.bach@17-custom.jar --main-class com.github.sormuras.[...]
Check main modules
  jdeps    --check com.github.sormuras.bach --multi-release BASE --module-path .bach\workspace\modules;.bach\external-modules
Generate API documentation
  javadoc  --module com.github.sormuras.bach --module-source-path .\*\main\java --module-path .bach\external-modules -encod[...]
  jar      --create --file .bach\workspace\documentation\bach-api-17-custom+20210325103746.zip --no-manifest -C .bach\works[...]
Generate and check Maven consumer POM file
Logbook written to file:///D:/dev/github/sormuras/bach/.bach/workspace/logbook.md
Exception in thread "main" java.lang.NoClassDefFoundError: bach/info/PomChecker
        at bach.info/bach.info.MainSpaceBuilder.buildProjectMainSpace(MainSpaceBuilder.java:21)
        at com.github.sormuras.bach@17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z/com.github.sormuras.bach.Bach.build(Bach.java:125)
        at com.github.sormuras.bach@17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z/com.github.sormuras.bach.Main.runAndReturnStatus(Main.java:131)
        at com.github.sormuras.bach@17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z/com.github.sormuras.bach.Main.run(Main.java:104)
        at com.github.sormuras.bach@17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z/com.github.sormuras.bach.Main.run(Main.java:99)
        at com.github.sormuras.bach@17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z/com.github.sormuras.bach.Main.run(Main.java:78)
        at com.github.sormuras.bach@17+BOOTSTRAP+2021-03-25T10:26:35.184249300Z/com.github.sormuras.bach.Main.main(Main.java:13)
Caused by: java.lang.ClassNotFoundException: bach.info.PomChecker
        at java.base/jdk.internal.loader.Loader.loadClass(Loader.java:566)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:519)
        ... 7 more