Merge commit 'ae6bdcc53584aaf20211ce1814bea97ece08a248'

# Conflicts:
#	nixpkgs/pkgs/build-support/rust/default.nix
#	nixpkgs/pkgs/development/go-modules/generic/default.nix

1 files changed, 16 insertions, 0 deletions

diff --git a/nixpkgs/lib/tests/modules/define-option-dependently.nix b/nixpkgs/lib/tests/modules/define-option-dependently.nix
new file mode 100644
index 000000000000..6abce29366ae
--- /dev/null
+++ b/nixpkgs/lib/tests/modules/define-option-dependently.nix
@@ -0,0 +1,16 @@
+{ lib, options, ... }:
+
+# Some modules may be distributed separately and need to adapt to other modules
+# that are distributed and versioned separately.
+{
+
+  # Always defined, but the value depends on the presence of an option.
+  config = {
+    value = if options ? enable then 360 else 7;
+  } 
+  # Only define if possible.
+  // lib.optionalAttrs (options ? enable) {
+    enable = true;
+  };
+
+}