Claiming that "it should literally never be used ever no matter what" is
confusing and wrong -- it's definitely useful sometimes, but does result
in downsides, like not tracking inter-target dependencies correctly.
Ref: #10901
It is often useful to check the found version of a program without
checking whether you can successfully find
`find_program('foo', required: false, version: '>=XXX')`
This is currently allowed, and is used in at least a few projects. It
was not intended to work or documented, but it does and since it is in
use a full deprecation period must be used. A warning has also been
added for values < 0, which have surprising behavior.
All kwargs inherited from has_header need to be prefixed `header_` so we
cannot just do straight inheritance. And the part of the description
that highlighted the way kwargs are derived and evolved, went entirely
missing.
Fixes#9551
In the refman rewrite, these functions vanished. I noticed this when I
went looking at the docs for extract_all_objects(), or should I say I
tried to go looking.