Windows: bash tool with piped POSIX commands (e.g. `| cat`) causes "Not enough memory resources are available to process this command"

[euxaristia]

Summary

On Windows, the agent frequently emits shell commands using POSIX-style pipes to utilities that don't exist in cmd.exe (or cause parse failures):

gh pr view 465 --json reviews,comments -q '.reviews | length' 2>&1 | cat
gh api repos/.../pulls/465/reviews 2>&1 | cat
go test -run 'TestFoo|Bar' ...

These fail with the unhelpful error:

Not enough memory resources are available to process this command.
exit 1

Root cause

• The model defaults to Unix idioms (| cat / | head to control output or bypass pagers, single quotes around args containing |).
• cmd.exe has no cat/head. Pipes to missing commands + unquoted metachars in the remainder passed to cmd /d /c lead to command-line parse errors that surface as this memory warning.
• Pre-flight detection only caught bare ls and cd /... paths. Piped utilities ran straight through.

This was reported via multiple TUI screenshots during PR review work (inspecting large review threads, etc.).

Fix on this branch

• Extended detectShellCommandIssue (with regex + string fallbacks) to flag piped POSIX utilities (head|tail|grep|cat|wc|...) before execution on Windows.
• Significantly improved guidance in the bash/exec_command tool descriptions and system <environment> block:
  • On Windows, wrap arguments containing | (or & > < ^) in double quotes: gh --jq ".foo | bar" (single quotes do not protect metachars in cmd.exe).
  • Prefer gh --jq / -q for server-side filtering, PowerShell Select-Object -First N for limiting output, or Zero's native tools (grep, read_file, glob, etc.).
• Better error suggestions when bad commands slip through.
• Complementary quoting fixes (/d /c raw command line, no temp script, no /s) so properly-quoted commands reach cmd.exe intact.

This prevents the bad patterns from ever being executed and teaches the model correct Windows shell usage going forward.

Changes

internal/tools/shell_runtime.go

• Added windowsPosixUtilityPattern (and kept/expanded coverage) to catch piped utilities early.
• Updated detectShellCommandIssue and suggestions.
• Enhanced shellGuidanceForGOOS with explicit Windows quoting advice for metachars in args.

internal/tools/bash_tool_test.go

• Added/updated tests for the new detection (piped POSIX, avoiding false positives on filenames like tail-log.sh).

internal/agent/system_prompt.go

• Improved the Windows shell syntax guidance in the environment block.

(Plus minor related cleanups in safe_command suggestions for Windows.)

Test plan

• go test ./internal/tools -run 'TestDetectShellCommandIssue' -count=1 — all pass (including new cases and "unrelated" filename cases).
• Manual: on Windows, ask the agent to inspect a PR with many comments or run go test -run 'A|B'. It now uses --jq or double-quoted filters and avoids | cat.
• The "memory" errors and wasted turns on | cat / | head no longer occur.

Fixes the class of issues seen in the attached screenshots during work on PRs #464/#465.

[Vasanthdev2004]

Closing as completed — #412 (flag piped POSIX utilities on Windows) added pre-flight detection for the POSIX coreutil family (head/tail/grep/cat/awk/sed/cut/xargs/tr/...) piped through cmd.exe, so instead of the cryptic "Not enough memory resources" error you now get a clear Windows-compatible suggestion before the turn runs. #587 is a follow-up still in review for the MSYS/WSL shell case. Reopen if a piped POSIX command still fails with the old error.