diff --git a/docker/tests/conftest.py b/docker/tests/conftest.py
index c3f8605..59b452b 100644
--- a/docker/tests/conftest.py
+++ b/docker/tests/conftest.py
@@ -1,153 +1,154 @@
 # Copyright (C) 2019-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import re
 import subprocess
 import time
 
 import requests
 
 from os.path import join
 from typing import Generator, Mapping, Tuple
 from urllib.parse import urljoin
 
 import pytest
 import testinfra
 
 
 APIURL = 'http://127.0.0.1:5080/api/1/'
 
 SAMPLE_METADATA = '''\
 <?xml version="1.0" encoding="utf-8"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
        xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0">
   <title>Test Software</title>
   <client>swh</client>
   <external_identifier>test-software</external_identifier>
   <codemeta:author>
     <codemeta:name>No One</codemeta:name>
   </codemeta:author>
 </entry>
 '''
 
 
 # scope='session' so we use the same container for all the tests;
 @pytest.fixture(scope='session')
 def docker_compose(request):
     # start the whole cluster
     subprocess.check_output(['docker-compose', 'up', '-d'])
     yield
     # and strop it
     subprocess.check_call(['docker-compose', 'down'])
 
 
 @pytest.fixture
 def scheduler_host(request, docker_compose):
     # run a container in which test commands are executed
     docker_id = subprocess.check_output(
         ['docker-compose', 'run', '-d',
          'swh-scheduler', 'shell', 'sleep', '1h']).decode().strip()
     scheduler_host = testinfra.get_host("docker://" + docker_id)
     scheduler_host.check_output('wait-for-it swh-scheduler:5008 -t 30')
     scheduler_host.check_output('wait-for-it swh-storage:5002 -t 30')
 
     # return a testinfra connection to the container
     yield scheduler_host
 
     # at the end of the test suite, destroy the container
     subprocess.check_call(['docker', 'rm', '-f', docker_id])
 
 
 # scope='session' so we use the same container for all the tests;
 @pytest.fixture
 def deposit_host(request, docker_compose):
     # run a container in which test commands are executed
     docker_id = subprocess.check_output(
         ['docker-compose', 'run', '-d',
          'swh-deposit', 'shell', 'sleep', '1h']).decode().strip()
     deposit_host = testinfra.get_host("docker://" + docker_id)
     deposit_host.check_output(
         'echo \'print("Hello World!")\n\' > /tmp/hello.py')
     deposit_host.check_output(
         'tar -C /tmp -czf /tmp/archive.tgz /tmp/hello.py')
     deposit_host.check_output(
         f'echo \'{SAMPLE_METADATA}\' > /tmp/metadata.xml')
     deposit_host.check_output('wait-for-it swh-deposit:5006 -t 30')
     # return a testinfra connection to the container
     yield deposit_host
 
     # at the end of the test suite, destroy the container
     subprocess.check_call(['docker', 'rm', '-f', docker_id])
 
 
 @pytest.fixture
 def git_url():
     return 'https://forge.softwareheritage.org/source/swh-core'
 
 
 @pytest.fixture
 def git_origin(scheduler_host, git_url):
     task = scheduler_host.check_output(
         'swh scheduler task add load-git '
         f'url={git_url}'
     )
     taskid = re.search(r'^Task (?P<id>\d+)$', task,
                        flags=re.MULTILINE).group('id')
     assert int(taskid) > 0
 
     for i in range(60):
         status = scheduler_host.check_output(
             f'swh scheduler task list --list-runs --task-id {taskid}')
         if 'Executions:' in status:
             if '[eventful]' in status:
                 break
             if '[started]' in status:
                 time.sleep(1)
                 continue
             if '[failed]' in status:
                 loader_logs = subprocess.check_output(
                     ['docker-compose', 'logs', 'swh-loader'])
                 assert False, ('Loading execution failed\n'
                                f'status: {status}\n'
-                               f'loader logs: {loader_logs}')
+                               f'loader logs: '
+                               + loader_logs.decode(errors='replace'))
             assert False, f'Loading execution failed, task status is {status}'
     return git_url
 
 
 # Utility functions
 
 def apiget(path: str, verb: str = 'GET', **kwargs):
     """Query the API at path and return the json result or raise an
     AssertionError"""
 
     url = urljoin(APIURL, path)
     resp = requests.request(verb, url, **kwargs)
     assert resp.status_code == 200, f'failed to retrieve {url} ({resp})'
     return resp.json()
 
 
 def pollapi(path: str, verb: str = 'GET', **kwargs):
     """Poll the API at path until it returns an OK result"""
     url = urljoin(APIURL, path)
     for i in range(60):
         resp = requests.request(verb, url, **kwargs)
         if resp.ok:
             break
         time.sleep(1)
     else:
         assert False, f"Polling {url} failed"
     return resp
 
 
 def getdirectory(dirid: str, currentpath: str = '') \
         -> Generator[Tuple[str, Mapping], None, None]:
     """Recursively retrieve directory description from the archive"""
     directory = apiget(f'directory/{dirid}')
     for direntry in directory:
         path = join(currentpath, direntry['name'])
         if direntry['type'] != 'dir':
             yield (path, direntry)
         else:
             yield from getdirectory(direntry['target'], path)