If you are running Checkstyle (for checking Java style) and you are stuck with this error:
checkstyle:
[checkstyle] Running Checkstyle 6.11.2 on 2324 files
[checkstyle] Can't find/access AST Node typecom.puppycrawl.tools.checkstyle.api.DetailAST
which is a cryptic error with no whatsoever Google result on how to fix it, stand back: I have the solution!
You probably have these packages installed in your system:
% rpm -qa | grep -i antlr
ant-antlr-1.9.4-9.2.noarch
antlr-java-2.7.7-103.38.noarch
antlr-2.7.7-103.38.x86_64
To fix your problem, just remove ant-antlr package from your system.