6 files changed, 67 insertions, 6 deletions
diff --git a/src/nix/build.cc b/src/nix/build.cc
index b4f21b32d78f..b329ac38ac2b 100644
--- a/src/nix/build.cc
+++ b/src/nix/build.cc
@@ -52,6 +52,8 @@ struct CmdBuild : MixDryRun, InstallablesCommand
     {
         auto buildables = build(store, dryRun ? DryRun : Build, installables);
 
+        if (dryRun) return;
+
         for (size_t i = 0; i < buildables.size(); ++i) {
             auto & b(buildables[i]);
 
diff --git a/src/nix/copy.cc b/src/nix/copy.cc
index 2ddea9e70a6a..f29429c1ac49 100644
--- a/src/nix/copy.cc
+++ b/src/nix/copy.cc
@@ -57,15 +57,15 @@ struct CmdCopy : StorePathsCommand
         return {
             Example{
                 "To copy Firefox from the local store to a binary cache in file:///tmp/cache:",
-                "nix copy --to file:///tmp/cache -r $(type -p firefox)"
+                "nix copy --to file:///tmp/cache $(type -p firefox)"
             },
             Example{
                 "To copy the entire current NixOS system closure to another machine via SSH:",
-                "nix copy --to ssh://server -r /run/current-system"
+                "nix copy --to ssh://server /run/current-system"
             },
             Example{
                 "To copy a closure from another machine via SSH:",
-                "nix copy --from ssh://server -r /nix/store/a6cnl93nk1wxnq84brbbwr6hxw9gp2w9-blender-2.79-rc2"
+                "nix copy --from ssh://server /nix/store/a6cnl93nk1wxnq84brbbwr6hxw9gp2w9-blender-2.79-rc2"
             },
         };
     }
diff --git a/src/nix/ls.cc b/src/nix/ls.cc
index 69620595d8ca..e99622faf472 100644
--- a/src/nix/ls.cc
+++ b/src/nix/ls.cc
@@ -90,6 +90,16 @@ struct CmdLsStore : StoreCommand, MixLs
         expectArg("path", &path);
     }
 
+    Examples examples() override
+    {
+        return {
+            Example{
+                "To list the contents of a store path in a binary cache:",
+                "nix ls-store --store https://cache.nixos.org/ -lR /nix/store/0i2jd68mp5g6h2sa5k9c85rb80sn8hi9-hello-2.10"
+            },
+        };
+    }
+
     std::string name() override
     {
         return "ls-store";
@@ -116,6 +126,16 @@ struct CmdLsNar : Command, MixLs
         expectArg("path", &path);
     }
 
+    Examples examples() override
+    {
+        return {
+            Example{
+                "To list a specific file in a NAR:",
+                "nix ls-nar -l hello.nar /bin/hello"
+            },
+        };
+    }
+
     std::string name() override
     {
         return "ls-nar";
diff --git a/src/nix/main.cc b/src/nix/main.cc
index 8f6bbe8f51ae..bb107ec7d3f6 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -92,6 +92,8 @@ void mainWrapped(int argc, char * * argv)
 
     args.parseCmdline(argvToStrings(argc, argv));
 
+    initPlugins();
+
     if (!args.command) args.showHelpAndExit();
 
     Finally f([]() { stopProgressBar(); });
diff --git a/src/nix/ping-store.cc b/src/nix/ping-store.cc
new file mode 100644
index 000000000000..310942574a2a
--- /dev/null
+++ b/src/nix/ping-store.cc
@@ -0,0 +1,35 @@
+#include "command.hh"
+#include "shared.hh"
+#include "store-api.hh"
+
+using namespace nix;
+
+struct CmdPingStore : StoreCommand
+{
+    std::string name() override
+    {
+        return "ping-store";
+    }
+
+    std::string description() override
+    {
+        return "test whether a store can be opened";
+    }
+
+    Examples examples() override
+    {
+        return {
+            Example{
+                "To test whether connecting to a remote Nix store via SSH works:",
+                "nix ping-store --store ssh://mac1"
+            },
+        };
+    }
+
+    void run(ref<Store> store) override
+    {
+        store->connect();
+    }
+};
+
+static RegisterCommand r1(make_ref<CmdPingStore>());
diff --git a/src/nix/run.cc b/src/nix/run.cc
index ade87e63a49c..d04e106e037b 100644
--- a/src/nix/run.cc
+++ b/src/nix/run.cc
@@ -16,8 +16,6 @@ using namespace nix;
 
 std::string chrootHelperName = "__run_in_chroot";
 
-extern char * * environ;
-
 struct CmdRun : InstallablesCommand
 {
     std::vector<std::string> command = { "bash" };
@@ -85,6 +83,10 @@ struct CmdRun : InstallablesCommand
                 "To run GNU Hello:",
                 "nix run nixpkgs.hello -c hello --greeting 'Hi everybody!'"
             },
+            Example{
+                "To run GNU Hello in a chroot store:",
+                "nix run --store ~/my-nix nixpkgs.hello -c hello"
+            },
         };
     }
 
@@ -105,7 +107,7 @@ struct CmdRun : InstallablesCommand
                 if (s) kept[var] = s;
             }
 
-            environ = nullptr;
+            clearEnv();
 
             for (auto & var : kept)
                 setenv(var.first.c_str(), var.second.c_str(), 1);