neteler
commented
2 years ago https://github.com/OSGeo/grass/blob/main/lib/gis/parser.c#L466
has been introduced in 8ffa3de2e2848f62abf88db850fdfbf275cabe2f.
Background
I could trace it back here (found by checking communication in "grass-dev" for the date of the above commit):
https://lists.osgeo.org/pipermail/grass-dev/2010-February/049096.html
which leads to the original ticket:
"module help information in machine-readable format" https://trac.osgeo.org/grass/ticket/953
BadAssassin
--help-text is an undocumented option for modules that outputs to stdout (stderr is default with --help). This option needs to be documented.