Flamenco-Management/.specstory/history/2025-11-21_01-14Z-workers-failing-and-ssh-connection-issues.md

Workers failing and SSH connection issues (2025-11-21 01:14Z)

User (2025-11-21 01:14Z)

all workers are failing?

Connecting to i9kf...

exec request failed on channel 0

SSH session ended.

Press Enter to close:

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Agent (model gpt-5.1-codex, mode Agent)

Thought Process

Checking workspace directory

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Tool use: **list_dir** • Listed directory, 0 results

No results found

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Thought Process

Diagnosing worker connection failures

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Tool use: **read_file** • Read file: scripts/TalkingHeads cycles_optix_gpu.js

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Thought Process

Checking for relevant scripts

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Tool use: **read_file** • Read file: scripts/outline.txt

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Thought Process

Investigating worker failure context

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Tool use: **read_file** • Read file: unified_flamenco_launcher.ps1

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Thought Process

Analyzing SSH exec request failure

I’m piecing together why the SSH “exec request failed on channel 0” error occurs when the script tries running powershell -EncodedCommand remotely. It looks like the remote hosts may lack PowerShell, use restrictive SSH configs, or have quoting and command invocation issues; I’m considering host OS differences, SSH subsystems, and command formatting problems to guide a helpful troubleshooting response.

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Tool use: **read_file** • Read file: unified_flamenco_launcher.bat

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Thought Process

Analyzing remote SSH exec failure

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Tool use: **grep** • Grep for "exec request failed" in "." • 0 matches

Output mode: content

No matches found

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Thought Process

Analyzing SSH exec failure causes

I'm gathering possible reasons why all workers fail with "exec request failed on channel 0," focusing on remote SSH command execution limits, shell configuration, command length limits on Windows, and potential remote server restrictions or misconfigurations. I’m considering the encoded PowerShell command size, quoting issues, remote subsystems, ForceCommand settings, and suggesting diagnostic steps to help troubleshoot the problem. Proposing remote script streaming approach

I'm exploring a way to fix the failure by modifying the script to stream the remote PowerShell code via SSH standard input instead of using long encoded commands, which may exceed length limits or cause quoting issues. I’m outlining implementation ideas to pipe the script through SSH to remote powershell -Command - to avoid exec errors and suggesting a plan to update the launcher accordingly. Detailing PowerShell SSH streaming implementation

I'm outlining a helper to stream the worker script to the remote PowerShell session via SSH by piping the script through standard input using Start-Process with redirected input. I’m carefully considering argument quoting, how to pass SSH options and commands, and PowerShell’s handling of reading scripts from stdin, while also weighing alternatives like copying a script file to the remote host for execution.

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Tool use: **run_terminal_cmd** • Run command: cd C:\Users\Nathan\Desktop\flamenco python - <<'PY' import re, base64 from pathlib import Path text = Path('unified_flamenco_launcher.ps1').read_text() patterns = [r"function Get-RemoteStandardWorkerCommand \{\s*@'([\s\S]+?)'@", r"function Get-RemoteCmdWorkerCommand \{\s*@'([\s\S]+?)'@", r"function Get-RemoteSimplifiedCmdWorkerCommand \{\s*@'([\s\S]+?)'@"] for pat in patterns: m = re.search(pat, text) if m: body = m.group(1) utf16 = body.encode('utf-16le') b64 = base64.b64encode(utf16) print(pat.split()[1], 'chars', len(body), 'utf16 bytes', len(utf16), 'b64 len', len(b64)) PY

cd C:\Users\Nathan\Desktop\flamenco
python - <<'PY'
import re, base64
from pathlib import Path
text = Path('unified_flamenco_launcher.ps1').read_text()
patterns = [r"function Get-RemoteStandardWorkerCommand \{\s*@'([\s\S]+?)'@", r"function Get-RemoteCmdWorkerCommand \{\s*@'([\s\S]+?)'@", r"function Get-RemoteSimplifiedCmdWorkerCommand \{\s*@'([\s\S]+?)'@"]
for pat in patterns:
    m = re.search(pat, text)
    if m:
        body = m.group(1)
        utf16 = body.encode('utf-16le')
        b64 = base64.b64encode(utf16)
        print(pat.split()[1], 'chars', len(body), 'utf16 bytes', len(utf16), 'b64 len', len(b64))
PY

ParserError: C:\Users\Nathan\AppData\Local\Temp\ps-script-4890d486-a555-41a3-8a38-e515f235a750.ps1:8
Line |
   8 |  python - <<'PY'
     |            ~
     | Missing file specification after redirection operator.

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Thought Process

Exploring PowerShell heredoc limits

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Tool use: **run_terminal_cmd** • Run command: cd C:\Users\Nathan\Desktop\flamenco python -c "import re, base64, pathlib; text = pathlib.Path('unified_flamenco_launcher.ps1').read_text(); import itertools patterns = ['function Get-RemoteStandardWorkerCommand {', 'function Get-RemoteCmdWorkerCommand {', 'function Get-RemoteSimplifiedCmdWorkerCommand {'] import sys for name in patterns: idx = text.find(name) if idx == -1: continue start = text.find("@'", idx) end = text.find("'@", start+2) body = text[start+2:end] utf16 = body.encode('utf-16le') b64 = base64.b64encode(utf16) print(name.split()[1], 'chars', len(body), 'utf16 bytes', len(utf16), 'b64 len', len(b64)) "

cd C:\Users\Nathan\Desktop\flamenco
python -c "import re, base64, pathlib; text = pathlib.Path('unified_flamenco_launcher.ps1').read_text();
import itertools
patterns = ['function Get-RemoteStandardWorkerCommand {', 'function Get-RemoteCmdWorkerCommand {', 'function Get-RemoteSimplifiedCmdWorkerCommand {']
import sys
for name in patterns:
    idx = text.find(name)
    if idx == -1:
        continue
    start = text.find("@'", idx)
    end = text.find("'@", start+2)
    body = text[start+2:end]
    utf16 = body.encode('utf-16le')
    b64 = base64.b64encode(utf16)
    print(name.split()[1], 'chars', len(body), 'utf16 bytes', len(utf16), 'b64 len', len(b64))
"

ParserError: C:\Users\Nathan\AppData\Local\Temp\ps-script-a0e83e85-1956-43ab-ab83-9ea6c4a2f958.ps1:16
Line |
  16 |      start = text.find("@'", idx)
     |                           ~
     | No characters are allowed after a here-string header but before the end of the line.

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Thought Process

Resolving PowerShell string parsing issues

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Tool use: **run_terminal_cmd** • Run command: cd C:\Users\Nathan\Desktop\flamenco @" import re, base64, pathlib text = pathlib.Path('unified_flamenco_launcher.ps1').read_text() patterns = ['function Get-RemoteStandardWorkerCommand {', 'function Get-RemoteCmdWorkerCommand {', 'function Get-RemoteSimplifiedCmdWorkerCommand {'] for name in patterns: idx = text.find(name) if idx == -1: continue start = text.find("@'", idx) end = text.find("'@", start+2) body = text[start+2:end] utf16 = body.encode('utf-16le') b64 = base64.b64encode(utf16) print(name.split()[1], 'chars', len(body), 'utf16 bytes', len(utf16), 'b64 len', len(b64)) "@ | Set-Content measure.py python measure.py Remove-Item measure.py

cd C:\Users\Nathan\Desktop\flamenco
@"
import re, base64, pathlib
text = pathlib.Path('unified_flamenco_launcher.ps1').read_text()
patterns = ['function Get-RemoteStandardWorkerCommand {', 'function Get-RemoteCmdWorkerCommand {', 'function Get-RemoteSimplifiedCmdWorkerCommand {']
for name in patterns:
    idx = text.find(name)
    if idx == -1:
        continue
    start = text.find("@'", idx)
    end = text.find("'@", start+2)
    body = text[start+2:end]
    utf16 = body.encode('utf-16le')
    b64 = base64.b64encode(utf16)
    print(name.split()[1], 'chars', len(body), 'utf16 bytes', len(utf16), 'b64 len', len(b64))
"@ | Set-Content measure.py
python measure.py
Remove-Item measure.py

Get-RemoteStandardWorkerCommand chars 2690 utf16 bytes 5380 b64 len 7176
Get-RemoteCmdWorkerCommand chars 2439 utf16 bytes 4878 b64 len 6504
Get-RemoteSimplifiedCmdWorkerCommand chars 2012 utf16 bytes 4024 b64 len 5368

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Thought Process

Evaluating remote SSH exec failure causes

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