ProGuard <https://github.com/Guardsquare/proguard> – a GPL2-licensed,
widely used JAR optimizer and obfuscator in the Android world – doesn't
work with `log4j-api` out of the box. In summary, since Log4j uses
reflection, ProGuard needs to be configured to avoid removing certain Log4j
classes. A user has submitted (#2182)
<https://github.com/apache/logging-log4j2/pull/2182> the ProGuard
configuration addressing the issue. We can either distribute it in
`META-INF/proguard/log4j.pro` and make `log4j-api` work out-of-the-box with
ProGoard or simply document this. Given how certain PMC members are
strongly allergic to breaking backward compatibility even in major
releases, I am afraid distributing this as a part of `log4j-api` will
become a liability we cannot get rid of in our lifetime. I will share this
with the user and ask him to convert his PR to a documentation update. If
you disagree, please let me know.
