nix app: Accept arguments

Example:

  $ nix app blender-bin -- --version
  Blender 2.80 (sub 74)

1 files changed, 7 insertions, 1 deletions

diff --git a/src/nix/run.cc b/src/nix/run.cc
index 62aae12f6..d30851d47 100644
--- a/src/nix/run.cc
+++ b/src/nix/run.cc
@@ -196,8 +196,11 @@ static RegisterCommand r1(make_ref<CmdRun>());
 
 struct CmdApp : InstallableCommand, RunCommon
 {
+    std::vector<std::string> args;
+
     CmdApp()
     {
+        expectArgs("args", &args);
     }
 
     std::string name() override
@@ -238,7 +241,10 @@ struct CmdApp : InstallableCommand, RunCommon
 
         state->realiseContext(app.context);
 
-        runProgram(store, app.program, {app.program});
+        Strings allArgs{app.program};
+        for (auto & i : args) allArgs.push_back(i);
+
+        runProgram(store, app.program, allArgs);
     }
 };