Added documentation for LINKER environment variable

This commit amends the documentation on environment variables to
reflect the proposed LINKER variable.

diff --git a/src/doc/src/reference/environment-variables.md b/src/doc/src/reference/environment-variables.md
index 3b505faa2e394bb288c7cf9069eeefd186299c92..455687a02b3a4c6e52edfa79a8d43676d8151fe1 100644 (file)
--- a/src/doc/src/reference/environment-variables.md
+++ b/src/doc/src/reference/environment-variables.md
@@ -123,6 +123,8 @@ let out_dir = env::var("OUT_DIR").unwrap();
 * `RUSTC`, `RUSTDOC` - the compiler and documentation generator that Cargo has
                        resolved to use, passed to the build script so it might
                        use it as well.
+* `LINKER` - The linker that rust has resolved to use for the current target,
+             passed to the build script so it might use it as well.
 
 [links]: reference/build-scripts.html#the-links-manifest-key
 [profile]: reference/manifest.html#the-profile-sections