Improve test failure output for lift-and-compare

bin/differential_tester_x86/LiftAndCompare.cpp

@@ -439,6 +439,9 @@ int main(int argc, char **argv) {
   std::vector<TestCase> failed_testcases;
   auto succeeded_tot = true;
   for (auto tc : testcases) {
+    llvm::errs() << llvm::toHex(tc.bytes) << "\n";
+    llvm::errs().flush();
+    
     auto tc_succeeded = runTestCase(tc, diffbuilder, whitelist, ++ctr);
     if (!tc_succeeded) {
       succeeded_tot = false;

scripts/diff_tester_export_insns/diff_tester_export_insns/ci_runner.py

@@ -8,6 +8,7 @@ import json
 import subprocess
 import tqdm
 import sys
+import shlex
 
 # paralellism for CI
 
@@ -43,6 +44,8 @@ class DiffTesterInfo:
         if exit_stat.returncode == 0:
             return TestResults(num_tests, 0)
 
+        sys.stderr.write(f"Command:\n{shlex.join(command_args)}\n")
+
         if exit_stat != 2:
             return TestResults(num_tests, num_tests)