Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -510,6 +510,12 @@
   ELFOptTable parser;
   opt::InputArgList args = parser.parse(argsArr.slice(1));
 
+
+  if (::getenv("FORCE_LLD_DIAGNOSTICS_CRASH")) {
+    message ("Crashing due to environment variable FORCE_LLD_DIAGNOSTICS_CRASH");
+    LLVM_BUILTIN_TRAP;
+  }
+
   // Interpret these flags early because error()/warn() depend on them.
   errorHandler().errorLimit = args::getInteger(args, OPT_error_limit, 20);
   errorHandler().fatalWarnings =
Index: lld/test/ELF/crash-report.test
===================================================================
--- /dev/null
+++ lld/test/ELF/crash-report.test
@@ -0,0 +1,9 @@
+//// Test the diagnostics produced when LLD crashes.
+
+//// Unset LLD_IN_TEST as its engages a crash recovery context.
+// RUN: env -u LLD_IN_TEST FORCE_LLD_DIAGNOSTICS_CRASH=1 not --crash ld.lld -o /dev/null 2>&1 | FileCheck %s
+
+//// Check the crash text has the correct structure.
+// CHECK: Crashing due to environment variable FORCE_LLD_DIAGNOSTICS_CRASH
+// CHECK: PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
+// CHECK: Stack dump: