Add nix crash command for testing crash reporting

Author: edolstra

src/nix/crash.cc

@@ -0,0 +1,48 @@
+#include "nix/cmd/command.hh"
+
+using namespace nix;
+
+struct CmdCrash : Command
+{
+    std::string type;
+
+    CmdCrash()
+    {
+        expectArg("type", &type);
+    }
+
+    Category category() override
+    {
+        return catUndocumented;
+    }
+
+    std::string description() override
+    {
+        return "crash the program to test crash reporting";
+    }
+
+    void run() override
+    {
+        if (type == "segfault") {
+            printError("Triggering a segfault...");
+            volatile int * p = nullptr;
+            *p = 123;
+        }
+
+        else if (type == "assert") {
+            printError("Triggering an assertion failure...");
+            assert(false && "This is an assertion failure");
+        }
+
+        else if (type == "logic-error") {
+            printError("Triggering a C++ logic error...");
+            std::bitset<4>{"012"};
+        }
+
+        else {
+            throw Error("unknown crash type '%s'", type);
+        }
+    }
+};
+
+static auto rCrash = registerCommand<CmdCrash>("crash");

src/nix/meson.build

@@ -68,6 +68,7 @@ nix_sources = [ config_priv_h ] + files(
   'config.cc',
   'copy.cc',
   'crash-handler.cc',
+  'crash.cc',
   'derivation-add.cc',
   'derivation-show.cc',
   'derivation.cc',