We support this in a machine file:
```
[binaries]
pkgconfig = 'pkg-config'
pkg-config = 'pkg-config'
```
and you can use either one, because internally we look up both. If you
only set *one* of them, this plays awkwardly with setting $PKG_CONFIG,
since we don't know which one you set in the machine file and the
*other* one will be initialized from the environment instead.
In commit 22df45a319 we changed program
lookup of config-tool style dependencies to use the regular tool names
and only fall back on the strange internal names. This affected the
pkg-config class too.
The result is that instead of preferring `pkgconfig =` followed by
$PKG_CONFIG followed by `pkg-config =`, we inverted the lookup order.
This is a good idea anyway, because now it behaves consistently with
`find_program('pkg-config')`.
Unfortunately, we documented the wrong name in a bunch of places, and
also used the wrong name in various testsuite bits, which meant that if
you set $PKG_CONFIG and then ran the testsuite, it would fail.
Correct these references, because they are buggy.
One test case expected to find_program() a native copy for convenience
of testing against natively installed glib. Force it to resolve a native
copy.
Meson internally knows about many languages and tools, and *FLAGS
variables, and which languages to use them for. Instead of duplicating
this logic, import it from mesonbuild.*
This logic was originally standalone, but now that it is merged into the
Meson tree we can have a single source of truth.
This reverts commit e257a870fe.
The PR adding this command had infinitely hanging CI, and now that it is
merged to master we cannot get any CI on any PR to succeed.
Luke Elliott