Disallow language keyword for unsupported deps.

Also, document it in the manual.

1 files changed, 1 insertions, 0 deletions

diff --git a/docs/markdown/Reference-manual.md b/docs/markdown/Reference-manual.md
index ebd7b39..265f76d 100644
--- a/docs/markdown/Reference-manual.md
+++ b/docs/markdown/Reference-manual.md
@@ -193,6 +193,7 @@ Finds an external dependency with the given name with `pkg-config` if possible a
 - `fallback` specifies a subproject fallback to use in case the dependency is not found in the system. The value is an array `['subproj_name', 'subproj_dep']` where the first value is the name of the subproject and the second is the variable name in that subproject that contains the value of [`declare_dependency`](#declare_dependency).
 - `default_options` *(added 0.37.0)* an array of option values that override those set in the project's `default_options` invocation (like `default_options` in [`project()`](#project), they only have effect when Meson is run for the first time, and command line arguments override any default options in build files)
 - `method` defines the way the dependency is detected, the default is `auto` but can be overridden to be e.g. `qmake` for Qt development, and different dependencies support different values for this (though `auto` will work on all of them)
+- `language` *(added 0.42.0)* defines what language-specific dependency to find if it's available for multiple languages.
 
 The returned object also has methods that are documented in the [object methods section](#dependency-object) below.