diff --git a/common/fuzzer_utils.py b/common/fuzzer_utils.py
index 049ba8ce3..b47e2860f 100644
--- a/common/fuzzer_utils.py
+++ b/common/fuzzer_utils.py
@@ -72,6 +72,12 @@ def dockerfiles(self):
 def get_fuzz_target_binary(search_directory: str,
                            fuzz_target_name: str) -> Optional[str]:
     """Return target binary path."""
+    logs.info(f'Searching for fuzz target binary named {fuzz_target_name} under'
+              f' directory {search_directory}')
+    logs.info(f'Search diretory {os.path.abspath(search_directory)} exists: '
+              f'{os.path.exists(os.path.abspath(search_directory))}')
+    logs.info(f'list Search diretory {search_directory}: '
+              f'{os.listdir(search_directory)}')
     if fuzz_target_name:
         fuzz_target_binary = os.path.join(search_directory, fuzz_target_name)
         if os.path.exists(fuzz_target_binary):
@@ -83,7 +89,11 @@ def get_fuzz_target_binary(search_directory: str,
     if os.path.exists(default_fuzz_target_binary):
         return default_fuzz_target_binary
 
+    logs.info('Searching for possible fuzz target in search directory: '
+              f'{search_directory}')
     for root, _, files in os.walk(search_directory):
+        logs.info(f'Searching for possible fuzz target under subdir {root}: '
+                  f'{files}')
         if root == 'uninstrumented':
             continue
         for filename in files:
diff --git a/experiment/build/gcb_build.py b/experiment/build/gcb_build.py
index f553848c7..8030f23dd 100644
--- a/experiment/build/gcb_build.py
+++ b/experiment/build/gcb_build.py
@@ -105,7 +105,8 @@ def _build(
         # TODO(metzman): Refactor code so that local_build stores logs as well.
         build_utils.store_build_logs(config_name, result)
         if result.retcode != 0:
-            logs.error('%s failed.', command)
+            logs.error('%s failed. Return code: %d. Output: %s. Timedout: %s',
+                       command, result.retcode, result.output, result.timed_out)
             raise subprocess.CalledProcessError(result.retcode, command)
     return result
 
diff --git a/experiment/measurer/coverage_utils.py b/experiment/measurer/coverage_utils.py
index 27ab69965..9f8e295c9 100644
--- a/experiment/measurer/coverage_utils.py
+++ b/experiment/measurer/coverage_utils.py
@@ -133,7 +133,9 @@ def merge_profdata_files(self):
 
         result = merge_profdata_files(files_to_merge, self.merged_profdata_file)
         if result.retcode != 0:
-            logger.error('Profdata files merging failed.')
+            logger.error(
+                f'Profdata files merging failed for (fuzzer, benchmark): '
+                f'({self.fuzzer}, {self.benchmark}).')
 
     def generate_coverage_summary_json(self):
         """Generates the coverage summary json from merged profdata file."""
diff --git a/experiment/runner.py b/experiment/runner.py
index b8c95fcca..776a4656e 100644
--- a/experiment/runner.py
+++ b/experiment/runner.py
@@ -177,10 +177,13 @@ def run_fuzzer(max_total_time, log_filename):
     input_corpus = environment.get('SEED_CORPUS_DIR')
     output_corpus = os.environ['OUTPUT_CORPUS_DIR']
     fuzz_target_name = environment.get('FUZZ_TARGET')
+    logs.info('all ENV VAR '
+              f'{[f"{key}: {value}" for key, value in os.environ.items()]}')
     target_binary = fuzzer_utils.get_fuzz_target_binary(FUZZ_TARGET_DIR,
                                                         fuzz_target_name)
     if not target_binary:
-        logs.error('Fuzz target binary not found.')
+        logs.error(f'Fuzz target binary {fuzz_target_name} not found under '
+                   f'{FUZZ_TARGET_DIR}')
         return
 
     if max_total_time is None:
diff --git a/service/gcbrun_experiment.py b/service/gcbrun_experiment.py
index f19ab493d..fa0313ec8 100644
--- a/service/gcbrun_experiment.py
+++ b/service/gcbrun_experiment.py
@@ -20,6 +20,7 @@
 import logging
 import os
 import sys
+# dummy
 
 # pytype: disable=import-error
 import github  # pylint: disable=import-error