This suggest that the --enable-maintainer-mode still should work.
However, when I try to pass it to configure I am getting:
configure: WARNING: unrecognized options: --enable-maintainer-mode.
What is wrong? Am I looking at the wrong/old documentation?
when I try to pass it to configure I am getting:
configure: WARNING: unrecognized options: --enable-maintainer-mode.What is wrong?
As the docs you linked describe, you must have the AM_MAINTAINER_MODE macro in your configure.in for maintainer-mode management to be available (otherwise, maintainer mode is on by default and cannot be disabled). The warning you present suggests that either you have not included that macro, or you have not re-run auto[re]conf since adding it.
Am I looking at the wrong/old documentation?
The link in your question appears to be to the current docs.