# MODULE FAILURE: No start of json char found

**URL:** <https://forum.ansible.com/t/module-failure-no-start-of-json-char-found/44275>\
**Category:** Get Help\
**Tags:** azure, ansible-project, ubuntu, galaxy-ng\
**Created:** [August 11, 2025, 6:33pm UTC](https://forum.ansible.com/t/module-failure-no-start-of-json-char-found/44275 "2025-08-11T18:33:10Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![basictheprogram](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/basictheprogram/32/9260_2.png) [@basictheprogram](https://forum.ansible.com/u/basictheprogram)\
**Post date:** [August 11, 2025, 6:33pm UTC](https://forum.ansible.com/t/module-failure-no-start-of-json-char-found/44275/1 "2025-08-11T18:33:10Z")

</div>

Upgrading from ansible-core-2.12 to ansible-11.8.0 (ansible-core-2.18.7) and basic tasks are failing. The issues seem to happen only in molecule testing.

I am working in a vscode devcontainer on macOS 15 and Docker Desktop

```auto
sw_vers 
ProductName: macOS
ProductVersion: 15.6
BuildVersion: 24G84

docker --version
Docker version 28.3.3-1, build 980b85681696fbd95927fd8ded8f6d91bdca95b0

docker desktop
4.44.0 (201307)

python -V
Python 3.13.6

ansible --version
ansible [core 2.18.7]
  config file = None
  configured module search path = ['/home/vscode/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vscode/.venv/lib/python3.13/site-packages/ansible
  ansible collection location = /home/vscode/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/vscode/.venv/bin/ansible
  python version = 3.13.6 (main, Aug 8 2025, 17:10:04) [Clang 20.1.4] (/home/vscode/.venv/bin/python)
  jinja version = 3.1.6
  libyaml = True

molecule --version
[DEPRECATION WARNING]: [defaults]collections_paths option. Reason: does not fit
 var naming standard, use the singular form collections_path instead 
Alternatives: none. This feature will be removed in version 2.19. Deprecation 
warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
 [DEPRECATED] [defaults]collections_paths option. Reason: does not fit var naming standard, use the singular form collections_path instead
Alternatives: none, to be removed in 2.19
molecule 25.7.0 using python 3.13 
    ansible:2.18.7
    docker:23.7.0 from molecule_plugins requiring collections: community.docker>=3.10.2 ansible.posix>=1.4.0
    gce:23.7.0 from molecule_plugins requiring collections: google.cloud>=1.0.2 community.crypto>=1.8.0
    podman:23.7.0 from molecule_plugins requiring collections: containers.podman>=1.7.0 ansible.posix>=1.3.0
    ec2:23.7.0 from molecule_plugins
    openstack:23.7.0 from molecule_plugins requiring collections: openstack.cloud>=2.1.0
    azure:23.7.0 from molecule_plugins
    vagrant:23.7.0 from molecule_plugins
    containers:23.7.0 from molecule_plugins requiring collections: ansible.posix>=1.3.0 community.docker>=1.9.1 containers.podman>=1.8.1
    default:25.7.0 from molecule

uv pip list | grep molecule-
molecule-plugins 23.7.0

```

My molecule converge.yml:

```auto
---
- name: Converge
  hosts: all
  gather_facts: true
  become: true

   pre_tasks:
    - name: Package update (apt)
      ansible.builtin.apt:
        update_cache: true
      changed_when: false
      when: ansible_os_family == 'Debian'``

```

Non-debug and non-verbose:

```auto
$ molecule converge 
WARNING Driver docker does not provide a schema.
WARNING Driver docker does not provide a schema.
INFO default ➜ discovery: scenario test matrix: dependency, create, prepare, converge
INFO default ➜ prerun: Performing prerun with role_name_check=0...
INFO default ➜ dependency: Starting
WARNING default ➜ dependency: Skipping, missing the requirements file.
WARNING default ➜ dependency: Skipping, missing the requirements file.
INFO default ➜ dependency: Completed
INFO default ➜ create: Starting
WARNING default ➜ create: Skipping, instances already created.
INFO default ➜ create: Completed
INFO default ➜ prepare: Starting
WARNING default ➜ prepare: Skipping, prepare playbook not configured.
INFO default ➜ prepare: Completed
INFO default ➜ converge: Starting
INFO default ➜ converge: ansible-playbook version: ansible-playbook 
  config file = None
  configured module search path = ['/home/vscode/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vscode/.venv/lib/python3.13/site-packages/ansible
  ansible collection location = /home/vscode/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/vscode/.venv/bin/ansible-playbook
  python version = 3.13.6 (main, Aug 8 2025, 17:10:04) (/home/vscode/.venv/bin/python)
  jinja version = 3.1.6
  libyaml = True
INFO Sanity checks: 'docker'

PLAY [Converge] ****************************************************************

TASK [Gathering Facts] *********************************************************
ok: [jammy]

TASK [Package update (apt)] ****************************************************
fatal: [jammy]: FAILED! => {"changed": false, "module_stderr": "", "module_stdout": "", "msg": "MODULE FAILURE: No start of json char found\nSee stdout/stderr for the exact error", "rc": 0}

PLAY RECAP *********************************************************************
jammy : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0

CRITICAL Ansible return code was 2, command was: ansible-playbook --inventory /home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory --skip-tags molecule-notest,notest /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/converge.yml[/dim]

```

Debug and verbose

```auto
$ MOLECULE_LOG_LEVEL=DEBUG MOLECULE_DEBUG=1 molecule converge -- -vvv
DEBUG default ➜ validate: Validating schema /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/molecule.yml.
WARNING Driver docker does not provide a schema.
DEBUG default ➜ validate: Validating schema /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/molecule.yml.
WARNING Driver docker does not provide a schema.
INFO default ➜ discovery: scenario test matrix: dependency, create, prepare, converge
INFO default ➜ prerun: Performing prerun with role_name_check=0...
INFO default ➜ dependency: Starting
WARNING default ➜ dependency: Skipping, missing the requirements file.
WARNING default ➜ dependency: Skipping, missing the requirements file.
INFO default ➜ dependency: Completed
INFO default ➜ create: Starting
WARNING default ➜ create: Skipping, instances already created.
INFO default ➜ create: Completed
INFO default ➜ prepare: Starting
WARNING default ➜ prepare: Skipping, prepare playbook not configured.
INFO default ➜ prepare: Completed
INFO default ➜ converge: Starting
INFO default ➜ converge: ansible-playbook version: ansible-playbook 
  config file = None
  configured module search path = ['/home/vscode/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vscode/.venv/lib/python3.13/site-packages/ansible
  ansible collection location = /home/vscode/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/vscode/.venv/bin/ansible-playbook
  python version = 3.13.6 (main, Aug 8 2025, 17:10:04) (/home/vscode/.venv/bin/python)
  jinja version = 3.1.6
  libyaml = True
INFO Sanity checks: 'docker'
DEBUG: ANSIBLE ENVIRONMENT:
ANSIBLE_CONFIG: /home/vscode/.ansible/tmp/molecule.ZdnW.default/ansible.cfg
ANSIBLE_FORCE_COLOR: '1'

DEBUG: MOLECULE ENVIRONMENT:
MOLECULE_DEBUG: 'True'
MOLECULE_DEPENDENCY_NAME: galaxy
MOLECULE_DRIVER_NAME: docker
MOLECULE_ENV_FILE: /workspace/collections/ansible_collections/realtime/logging/roles/alloy/.env.yml
MOLECULE_EPHEMERAL_DIRECTORY: /home/vscode/.ansible/tmp/molecule.ZdnW.default
MOLECULE_FILE: /home/vscode/.ansible/tmp/molecule.ZdnW.default/molecule.yml
MOLECULE_INSTANCE_CONFIG: /home/vscode/.ansible/tmp/molecule.ZdnW.default/instance_config.yml
MOLECULE_INVENTORY_FILE: /home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory/ansible_inventory.yml
MOLECULE_LOG_LEVEL: DEBUG
MOLECULE_PROJECT_DIRECTORY: /workspace/collections/ansible_collections/realtime/logging/roles/alloy
MOLECULE_PROVISIONER_NAME: ansible
MOLECULE_SCENARIO_DIRECTORY: /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default
MOLECULE_SCENARIO_NAME: default
MOLECULE_STATE_FILE: /home/vscode/.ansible/tmp/molecule.ZdnW.default/state.yml
MOLECULE_VERIFIER_NAME: ansible
MOLECULE_VERIFIER_TEST_DIRECTORY: /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/tests

DEBUG: SHELL REPLAY:
ANSIBLE_CONFIG=/home/vscode/.ansible/tmp/molecule.ZdnW.default/ansible.cfg ANSIBLE_FORCE_COLOR=1 MOLECULE_DEBUG=True MOLECULE_DEPENDENCY_NAME=galaxy MOLECULE_DRIVER_NAME=docker MOLECULE_ENV_FILE=/workspace/collections/ansible_collections/realtime/logging/roles/alloy/.env.yml MOLECULE_EPHEMERAL_DIRECTORY=/home/vscode/.ansible/tmp/molecule.ZdnW.default MOLECULE_FILE=/home/vscode/.ansible/tmp/molecule.ZdnW.default/molecule.yml MOLECULE_INSTANCE_CONFIG=/home/vscode/.ansible/tmp/molecule.ZdnW.default/instance_config.yml MOLECULE_INVENTORY_FILE=/home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory/ansible_inventory.yml MOLECULE_LOG_LEVEL=DEBUG MOLECULE_PROJECT_DIRECTORY=/workspace/collections/ansible_collections/realtime/logging/roles/alloy MOLECULE_PROVISIONER_NAME=ansible MOLECULE_SCENARIO_DIRECTORY=/workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default MOLECULE_SCENARIO_NAME=default MOLECULE_STATE_FILE=/home/vscode/.ansible/tmp/molecule.ZdnW.default/state.yml MOLECULE_VERIFIER_NAME=ansible MOLECULE_VERIFIER_TEST_DIRECTORY=/workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/tests
ansible-playbook [core 2.18.7]
  config file = /home/vscode/.ansible/tmp/molecule.ZdnW.default/ansible.cfg
  configured module search path = ['/home/vscode/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vscode/.venv/lib/python3.13/site-packages/ansible
  ansible collection location = /home/vscode/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/vscode/.venv/bin/ansible-playbook
  python version = 3.13.6 (main, Aug 8 2025, 17:10:04) [Clang 20.1.4] (/home/vscode/.venv/bin/python)
  jinja version = 3.1.6
  libyaml = True
Using /home/vscode/.ansible/tmp/molecule.ZdnW.default/ansible.cfg as config file
host_list declined parsing /home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory/ansible_inventory.yml as it did not pass its verify_file() method
script declined parsing /home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory/ansible_inventory.yml as it did not pass its verify_file() method
Parsed /home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory/ansible_inventory.yml inventory source with yaml plugin
Skipping callback 'default', as we already have a stdout callback.
Skipping callback 'minimal', as we already have a stdout callback.
Skipping callback 'oneline', as we already have a stdout callback.
1 plays in /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/converge.yml

PLAYBOOK: converge.yml *********************************************************

PLAY [Converge] ****************************************************************

TASK [Gathering Facts] *********************************************************
task path: /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/converge.yml:2
<jammy> ESTABLISH DOCKER CONNECTION FOR USER: root
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', '/bin/sh -c \'( umask 77 && mkdir -p "` echo /tmp/.ansible/tmp `"&& mkdir "` echo /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695 `" && echo ansible-tmp-1754933818.4667227-8682-116366923936695="` echo /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695 `" ) && sleep 0\'']
<jammy> Attempting python interpreter discovery
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', '/bin/sh -c \'echo PLATFORM; uname; echo FOUND; command -v \'"\'"\'python3.13\'"\'"\'; command -v \'"\'"\'python3.12\'"\'"\'; command -v \'"\'"\'python3.11\'"\'"\'; command -v \'"\'"\'python3.10\'"\'"\'; command -v \'"\'"\'python3.9\'"\'"\'; command -v \'"\'"\'python3.8\'"\'"\'; command -v \'"\'"\'/usr/bin/python3\'"\'"\'; command -v \'"\'"\'python3\'"\'"\'; echo ENDFOUND && sleep 0\'']
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', "/bin/sh -c '/usr/bin/python3.10 && sleep 0'"]
<jammy> Python interpreter discovery fallback (unsupported Linux distribution: ubuntu)
Using module file /home/vscode/.venv/lib/python3.13/site-packages/ansible/modules/setup.py
<jammy> PUT /home/vscode/.ansible/tmp/ansible-local-8664b5y3y493/tmptz86g5en TO /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695/AnsiballZ_setup.py
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', "/bin/sh -c 'chmod u+rwx /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695/ /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695/AnsiballZ_setup.py && sleep 0'"]
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', '/bin/sh -c \'sudo -H -S -n -u root /bin/sh -c \'"\'"\'echo BECOME-SUCCESS-sgxabdpfbzvvrdmmvprdiovxdgpnrxsc ; /usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695/AnsiballZ_setup.py\'"\'"\' && sleep 0\'']
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', "/bin/sh -c 'rm -f -r /tmp/.ansible/tmp/ansible-tmp-1754933818.4667227-8682-116366923936695/ > /dev/null 2>&1 && sleep 0'"]
ok: [jammy]

TASK [Package update (apt)] ****************************************************
task path: /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/converge.yml:10
<jammy> ESTABLISH DOCKER CONNECTION FOR USER: root
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', '/bin/sh -c \'( umask 77 && mkdir -p "` echo /tmp/.ansible/tmp `"&& mkdir "` echo /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890 `" && echo ansible-tmp-1754933819.4123073-8800-78678785547890="` echo /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890 `" ) && sleep 0\'']
Using module file /home/vscode/.venv/lib/python3.13/site-packages/ansible/modules/apt.py
<jammy> PUT /home/vscode/.ansible/tmp/ansible-local-8664b5y3y493/tmpx1zu_qvj TO /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890/AnsiballZ_apt.py
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', "/bin/sh -c 'chmod u+rwx /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890/ /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890/AnsiballZ_apt.py && sleep 0'"]
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', '/bin/sh -c \'sudo -H -S -n -u root /bin/sh -c \'"\'"\'echo BECOME-SUCCESS-stqmenxchjgirbmsuaaohbfkmdkeiodt ; /usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890/AnsiballZ_apt.py\'"\'"\' && sleep 0\'']
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', "/bin/sh -c 'rm -f -r /tmp/.ansible/tmp/ansible-tmp-1754933819.4123073-8800-78678785547890/ > /dev/null 2>&1 && sleep 0'"]
fatal: [jammy]: FAILED! => {
    "changed": false,
    "module_stderr": "",
    "module_stdout": "",
    "msg": "MODULE FAILURE: No start of json char found\nSee stdout/stderr for the exact error",
    "rc": 0
}

PLAY RECAP *********************************************************************
jammy : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0

CRITICAL Ansible return code was 2, command was: ansible-playbook --diff --inventory /home/vscode/.ansible/tmp/molecule.ZdnW.default/inventory --skip-tags molecule-notest,notest -vvv /workspace/collections/ansible_collections/realtime/logging/roles/alloy/molecule/default/converge.yml[/dim]

```

I followed many of the posts I could find regarding “No start of json char found” and spent a lot of time with GPT-5 without any success. The posts and GPT keep stating this issue is a container problem. I do not agree.

Interactive shell and CLI works as expected. Ansible `raw` works:

```auto
---
- name: Converge
  hosts: all
  gather_facts: true
  become: true

  pre_tasks:
    - name: Update
      raw: |
        DEBIAN_FRONTEND=noninteractive apt-get update

```

```auto
$ molecule converge 
WARNING Driver docker does not provide a schema.
WARNING Driver docker does not provide a schema.
INFO default ➜ discovery: scenario test matrix: dependency, create, prepare, converge
INFO default ➜ prerun: Performing prerun with role_name_check=0...
INFO default ➜ dependency: Starting
WARNING default ➜ dependency: Skipping, missing the requirements file.
WARNING default ➜ dependency: Skipping, missing the requirements file.
INFO default ➜ dependency: Completed
INFO default ➜ create: Starting
WARNING default ➜ create: Skipping, instances already created.
INFO default ➜ create: Completed
INFO default ➜ prepare: Starting
WARNING default ➜ prepare: Skipping, prepare playbook not configured.
INFO default ➜ prepare: Completed
INFO default ➜ converge: Starting
INFO default ➜ converge: ansible-playbook version: ansible-playbook 
  config file = None
  configured module search path = ['/home/vscode/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vscode/.venv/lib/python3.13/site-packages/ansible
  ansible collection location = /home/vscode/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/vscode/.venv/bin/ansible-playbook
  python version = 3.13.6 (main, Aug 8 2025, 17:10:04) (/home/vscode/.venv/bin/python)
  jinja version = 3.1.6
  libyaml = True
INFO Sanity checks: 'docker'

PLAY [Converge] ****************************************************************

TASK [Gathering Facts] *********************************************************
ok: [jammy]

TASK [Update] ******************************************************************
changed: [jammy]

PLAY RECAP *********************************************************************
jammy : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

INFO default ➜ converge: Completed
(ansible-playbooks) vscode ➜ .../realtime/logging/roles/alloy (main) $ molecule converge 
WARNING Driver docker does not provide a schema.
WARNING Driver docker does not provide a schema.
INFO default ➜ discovery: scenario test matrix: dependency, create, prepare, converge
INFO default ➜ prerun: Performing prerun with role_name_check=0...
INFO default ➜ dependency: Starting
WARNING default ➜ dependency: Skipping, missing the requirements file.
WARNING default ➜ dependency: Skipping, missing the requirements file.
INFO default ➜ dependency: Completed
INFO default ➜ create: Starting
WARNING default ➜ create: Skipping, instances already created.
INFO default ➜ create: Completed
INFO default ➜ prepare: Starting
WARNING default ➜ prepare: Skipping, prepare playbook not configured.
INFO default ➜ prepare: Completed
INFO default ➜ converge: Starting
INFO default ➜ converge: ansible-playbook version: ansible-playbook 
  config file = None
  configured module search path = ['/home/vscode/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vscode/.venv/lib/python3.13/site-packages/ansible
  ansible collection location = /home/vscode/.ansible/collections:/usr/share/ansible/collections
  executable location = /home/vscode/.venv/bin/ansible-playbook
  python version = 3.13.6 (main, Aug 8 2025, 17:10:04) (/home/vscode/.venv/bin/python)
  jinja version = 3.1.6
  libyaml = True
INFO Sanity checks: 'docker'

PLAY [Converge] ****************************************************************

TASK [Gathering Facts] *********************************************************
ok: [jammy]

TASK [Update] ******************************************************************
changed: [jammy]

PLAY RECAP *********************************************************************
jammy : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

INFO default ➜ converge: Completed

```

Any help would be appreciated.

I think this is a molecule problem, but I am starting here.

---

<div class="post-metadata">

**Author:** ![basictheprogram](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/basictheprogram/32/9260_2.png) [@basictheprogram](https://forum.ansible.com/u/basictheprogram)\
**Post date:** [August 11, 2025, 6:56pm UTC](https://forum.ansible.com/t/module-failure-no-start-of-json-char-found/44275/2 "2025-08-11T18:56:02Z")

</div>

I continued troubleshooting. Testing playbook.

```auto
---
- name: Testing
  hosts: all
  connection: docker
  gather_facts: false

  tasks:
    - name: Check curl installed with apt module
      ansible.builtin.apt:
        name: curl
        state: present

```

```auto
$ export ANSIBLE_KEEP_REMOTE_FILES=1
$ ansible-playbook -i jammy, -c docker -e ansible_python_interpreter=/usr/bin/python3 playbooks/test-docker-connection.yml -vvvv -u root
<snip>
fatal: [jammy]: FAILED! => {
    "changed": false,
    "module_stderr": "",
    "module_stdout": "",
    "msg": "MODULE FAILURE: No start of json char found\nSee stdout/stderr for the exact error",
    "rc": 0
}

```

Consoled into the jammy docker container

```auto
# cd /root/.ansible/tmp/ansible-tmp-1754937943.4795835-12970-16199230815528
python3 AnsiballZ_apt.py 
                            <== THIS BLANK LINE
{"changed": false, "cache_updated": false, "cache_update_time": 1754936712, "invocation": {"module_args": {"name": "curl", "state": "present", "package": ["curl"], "update_cache_retries": 5, "update_cache_retry_max_delay": 12, "cache_valid_time": 0, "purge": false, "force": false, "upgrade": null, "dpkg_options": "force-confdef,force-confold", "autoremove": false, "autoclean": false, "fail_on_autoremove": false, "only_upgrade": false, "force_apt_get": false, "clean": false, "allow_unauthenticated": false, "allow_downgrade": false, "allow_change_held_packages": false, "lock_timeout": 60, "update_cache": null, "deb": null, "default_release": null, "install_recommends": null, "policy_rc_d": null}}}

```

I think the problem is that blank line?

```auto
python3 -u AnsiballZ_apt.py | hexdump -C
00000000 0a 7b 22 63 68 61 6e 67 65 64 22 3a 20 66 61 6c |.{"changed": fal|
00000010 73 65 2c 20 22 63 61 63 68 65 5f 75 70 64 61 74 |se, "cache_updat|

<snip>

```

leading `0a` byte at the very start is a newline character

---

<div class="post-metadata">

**Author:** ![basictheprogram](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/basictheprogram/32/9260_2.png) [@basictheprogram](https://forum.ansible.com/u/basictheprogram)\
**Post date:** [August 12, 2025, 12:44am UTC](https://forum.ansible.com/t/module-failure-no-start-of-json-char-found/44275/3 "2025-08-12T00:44:20Z")

</div>

More troubleshooting. Controlling tty issue in the docker connector? Keep the remote files so I can troubleshoot with them

```auto
$ export ANSIBLE_KEEP_REMOTE_FILES=1
$ docker exec jammy /usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754952848.1407292-87096-56280954989641/AnsiballZ_apt.py
$ echo $?
0

```

Give docker

`-i` is for interactive (keep STDIN open)

`-t` allocates a pseudo-TTY, which can change how buffering and output behave

```auto
$ docker exec -it jammy /usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754952848.1407292-87096-56280954989641/AnsiballZ_apt.py

{"changed": false, "cache_updated": false, "cache_update_time": 1754953554, "invocation": {"module_args": {"update_cache": true, "state": "present", "update_cache_retries": 5, "update_cache_retry_max_delay": 12, "cache_valid_time": 0, "purge": false, "force": false, "upgrade": null, "dpkg_options": "force-confdef,force-confold", "autoremove": false, "autoclean": false, "fail_on_autoremove": false, "only_upgrade": false, "force_apt_get": false, "clean": false, "allow_unauthenticated": false, "allow_downgrade": false, "allow_change_held_packages": false, "lock_timeout": 60, "package": null, "deb": null, "default_release": null, "install_recommends": null, "policy_rc_d": null}}}

```

ansible/plugins/action/\__init_\_.py:1533

```python
        rc, stdout, stderr = self._connection.exec_command(
            cmd, in_data=in_data, sudoable=sudoable
        )
        print(f"rc={rc}::stdout={stdout}::stderr={stderr}::cmd={cmd}")

```

There is no output on stdout and stderr? See the docker interactive flag but not the tty flag.

```auto
<jammy> EXEC ['/usr/bin/docker', b'exec', b'-i', 'jammy', '/bin/sh', '-c', "/bin/sh -c '/usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754954072.5935555-91591-205244058283265/AnsiballZ_apt.py && sleep 0'"] 

rc=0::stdout=b''::stderr=b''::cmd=/bin/sh -c '/usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754954072.5935555-91591-205244058283265/AnsiballZ_apt.py && sleep 0' [], 'stderr': '', 'stderr_lines': 

[]} fatal: [jammy]: FAILED! => { "changed": false, "module_stderr": "", "module_stdout": "", "msg": "MODULE FAILURE: 1 No start of json char found\nSee stdout/stderr for the exact error", "rc": 0 }

```

Only the interactive flag does output to stdout

```auto
$ docker exec -i jammy /usr/bin/python3.10 /tmp/.ansible/tmp/ansible-tmp-1754952848.1407292-87096-56280954989641/AnsiballZ_apt.py

{"changed": false, "cache_updated": false, "cache_update_time": 1754953554, "invocation": {"module_args": {"update_cache": true, "state": "present", "update_cache_retries": 5, "update_cache_retry_max_delay": 12, "cache_valid_time": 0, "purge": false, "force": false, "upgrade": null, "dpkg_options": "force-confdef,force-confold", "autoremove": false, "autoclean": false, "fail_on_autoremove": false, "only_upgrade": false, "force_apt_get": false, "clean": false, "allow_unauthenticated": false, "allow_downgrade": false, "allow_change_held_packages": false, "lock_timeout": 60, "package": null, "deb": null, "default_release": null, "install_recommends": null, "policy_rc_d": null}}}

```