The pkg-config variables have been added in GLib 2.62.0. Let's fallback to default names for these tools in such case (`pkg-config` still returns a 0 return value, but with empty output for absent variables).
The pkg-config variables have been added in GLib 2.62.0. Let's fallback to default names for these tools in such case (`pkg-config` still returns a 0 return value, but with empty output for absent variables).