Bug type
Regression (worked before, now fails)
Beta release blocker
No
Summary
Version
• OpenClaw updated to 2026.3.28
Symptoms
• read worked
• edit failed
• write failed
Observed errors
Gateway log showed:
• error [tools] edit failed: moltbot-sandbox-fs: 2: python3: not found
• error [tools] write failed: moltbot-sandbox-fs: 2: python3: not found
What was verified
• Host Python exists and is healthy:
• /usr/bin/python3
• This was not a host PATH issue
• This was not file-type specific (not related to markdown)
Root cause found
OpenClaw’s file mutation helper runs inside the Docker sandbox container.
Inspection of OpenClaw code showed the helper path invoking Docker sandbox shell execution, and the active sandbox container was based on:
• openclaw-sandbox:bookworm-slim
Inside the main sandbox container:
• which python3 returned no result / NO_PYTHON
Because moltbot-sandbox-fs requires python3, file mutation tools failed even though host Python was present.
Additional constraint
The live sandbox filesystem was read-only, so runtime repair with apt-get install python3 inside the container was not viable.
Local durable fix
I rebuilt the local image tagged openclaw-sandbox:bookworm-slim from debian:bookworm-slim with python3 installed, removed the old openclaw-sbx-* containers, restarted the gateway, and write succeeded again immediately.
Expected
The default sandbox image used by OpenClaw should include the dependencies required by moltbot-sandbox-fs, or OpenClaw should fail earlier with a clearer diagnostic / build the proper image automatically.
Actual
A default-tagged sandbox image without python3 caused edit/write to fail while read still worked.
Question
Is python3 an intended dependency of the default sandbox image for file mutation tools? If yes, can the default sandbox image build/package path be corrected or validated automatically?
Steps to reproduce
Observed errors
Gateway log showed:
• error [tools] edit failed: moltbot-sandbox-fs: 2: python3: not found
• error [tools] write failed: moltbot-sandbox-fs: 2: python3: not found
What was verified
• Host Python exists and is healthy:
• /usr/bin/python3
• This was not a host PATH issue
• This was not file-type specific (not related to markdown)
Root cause found
OpenClaw’s file mutation helper runs inside the Docker sandbox container.
Inspection of OpenClaw code showed the helper path invoking Docker sandbox shell execution, and the active sandbox container was based on:
• openclaw-sandbox:bookworm-slim
Inside the main sandbox container:
• which python3 returned no result / NO_PYTHON
Because moltbot-sandbox-fs requires python3, file mutation tools failed even though host Python was present.
Additional constraint
The live sandbox filesystem was read-only, so runtime repair with apt-get install python3 inside the container was not viable.
Local durable fix
I rebuilt the local image tagged openclaw-sandbox:bookworm-slim from debian:bookworm-slim with python3 installed, removed the old openclaw-sbx-* containers, restarted the gateway, and write succeeded again immediately.
Expected behavior
Expected
The default sandbox image used by OpenClaw should include the dependencies required by moltbot-sandbox-fs, or OpenClaw should fail earlier with a clearer diagnostic / build the proper image automatically.
Actual behavior
Actual
A default-tagged sandbox image without python3 caused edit/write to fail while read still worked.
OpenClaw version
OpenClaw updated to 2026.3.28
Operating system
Telegram/VPS/Windows
Install method
No response
Model
/
Provider / routing chain
/
Additional provider/model setup details
No response
Logs, screenshots, and evidence
Impact and severity
No response
Additional information
No response
Bug type
Regression (worked before, now fails)
Beta release blocker
No
Summary
Version
• OpenClaw updated to 2026.3.28
Symptoms
• read worked
• edit failed
• write failed
Observed errors
Gateway log showed:
• error [tools] edit failed: moltbot-sandbox-fs: 2: python3: not found
• error [tools] write failed: moltbot-sandbox-fs: 2: python3: not found
What was verified
• Host Python exists and is healthy:
• /usr/bin/python3
• This was not a host PATH issue
• This was not file-type specific (not related to markdown)
Root cause found
OpenClaw’s file mutation helper runs inside the Docker sandbox container.
Inspection of OpenClaw code showed the helper path invoking Docker sandbox shell execution, and the active sandbox container was based on:
• openclaw-sandbox:bookworm-slim
Inside the main sandbox container:
• which python3 returned no result / NO_PYTHON
Because moltbot-sandbox-fs requires python3, file mutation tools failed even though host Python was present.
Additional constraint
The live sandbox filesystem was read-only, so runtime repair with apt-get install python3 inside the container was not viable.
Local durable fix
I rebuilt the local image tagged openclaw-sandbox:bookworm-slim from debian:bookworm-slim with python3 installed, removed the old openclaw-sbx-* containers, restarted the gateway, and write succeeded again immediately.
Expected
The default sandbox image used by OpenClaw should include the dependencies required by moltbot-sandbox-fs, or OpenClaw should fail earlier with a clearer diagnostic / build the proper image automatically.
Actual
A default-tagged sandbox image without python3 caused edit/write to fail while read still worked.
Question
Is python3 an intended dependency of the default sandbox image for file mutation tools? If yes, can the default sandbox image build/package path be corrected or validated automatically?
Steps to reproduce
Observed errors
Gateway log showed:
• error [tools] edit failed: moltbot-sandbox-fs: 2: python3: not found
• error [tools] write failed: moltbot-sandbox-fs: 2: python3: not found
What was verified
• Host Python exists and is healthy:
• /usr/bin/python3
• This was not a host PATH issue
• This was not file-type specific (not related to markdown)
Root cause found
OpenClaw’s file mutation helper runs inside the Docker sandbox container.
Inspection of OpenClaw code showed the helper path invoking Docker sandbox shell execution, and the active sandbox container was based on:
• openclaw-sandbox:bookworm-slim
Inside the main sandbox container:
• which python3 returned no result / NO_PYTHON
Because moltbot-sandbox-fs requires python3, file mutation tools failed even though host Python was present.
Additional constraint
The live sandbox filesystem was read-only, so runtime repair with apt-get install python3 inside the container was not viable.
Local durable fix
I rebuilt the local image tagged openclaw-sandbox:bookworm-slim from debian:bookworm-slim with python3 installed, removed the old openclaw-sbx-* containers, restarted the gateway, and write succeeded again immediately.
Expected behavior
Expected
The default sandbox image used by OpenClaw should include the dependencies required by moltbot-sandbox-fs, or OpenClaw should fail earlier with a clearer diagnostic / build the proper image automatically.
Actual behavior
Actual
A default-tagged sandbox image without python3 caused edit/write to fail while read still worked.
OpenClaw version
OpenClaw updated to 2026.3.28
Operating system
Telegram/VPS/Windows
Install method
No response
Model
/
Provider / routing chain
/
Additional provider/model setup details
No response
Logs, screenshots, and evidence
Impact and severity
No response
Additional information
No response