## Yielding subproject option to superproject | |
Normally project options are specific to the current project. However | |
sometimes you want to have an option whose value is the same over all | |
projects. This can be achieved with the new `yield` keyword for | |
options. When set to `true`, getting the value of this option in | |
`meson.build` files gets the value from the option with the same name | |
in the master project (if such an option exists). |