From 1827cf5a9b8fa0f8f1dff1ee775f67f7f326606c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Na=C3=AFm=20Favier?= <n@monade.li>
Date: Mon, 20 Dec 2021 19:57:48 +0100
Subject: [PATCH] Add shell completion for why-depends

Fixes #5806
---
 src/nix/why-depends.cc | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/nix/why-depends.cc b/src/nix/why-depends.cc
index 2f6b361bb..e27f56ef5 100644
--- a/src/nix/why-depends.cc
+++ b/src/nix/why-depends.cc
@@ -34,8 +34,21 @@ struct CmdWhyDepends : SourceExprCommand
 
     CmdWhyDepends()
     {
-        expectArg("package", &_package);
-        expectArg("dependency", &_dependency);
+        expectArgs({
+            .label = "package",
+            .handler = {&_package},
+            .completer = {[&](size_t, std::string_view prefix) {
+                completeInstallable(prefix);
+            }}
+        });
+
+        expectArgs({
+            .label = "dependency",
+            .handler = {&_dependency},
+            .completer = {[&](size_t, std::string_view prefix) {
+                completeInstallable(prefix);
+            }}
+        });
 
         addFlag({
             .longName = "all",