tree 1f9a0bccf5ab23ff15eb38c26bda8c9d4e3dfb3d
parent 4a370aa1fe7a2fcafc41c0cd1bb4bf59bfb070a2
author Josh Bleecher Snyder <josharian@gmail.com> 1753399371 -0700
committer Josh Bleecher Snyder <josharian@gmail.com> 1753900210 -0700

claude: bash tool smorgasbord

This is a combination of a bunch of changes and bug fixes
accumulated over a week. It decided not to spend a bunch of time
teasing it apart into its components. I apologize.

Significant changes include:

- clean up background bash execution
- improve documentation
- remove TODO we're not gonna do
- add a "process completed" note to stderr
- convert background result printing to xml-ish
- combine stdout and stderr in background bash to match foreground use
- hint to sketch to kill the process group
- add missing timeouts propagation
- tell agent that bash calls are stateless
- thread pwd through explicitly
- unify command creation
- speed up missing command installation
    I tried a bunch of different ways to prompt engineer this to be faster.
    But Claude will be Claude. Solution: switch from agent to one-shot.

    This is marginally more brittle, and can only use a package manager,
    but that also prevents a bunch of possible curl|bash mess, etc.
    And this was always best-effort anyway.

    It's now MUCH faster to fail on non-existent commands, and about 2x
    faster on the real commands I tried (yamllint, htop)...now mostly down
    to the irreducible work involved in actually doing the installation.
- remove SKETCH_ from bash env, except SKETCH_PROXY_ID
- delay kill instructions until actually needed
- add simple GIT_SEQUENCE_EDITOR
- overhaul cancellation
- explicitly disable EDITOR to prevent hangs
    I have big plans here, but this will do for now.
- simplify and unify handling of long outputs
- switch to center trunctation of long outputs
- add zombie process cleanup using unix.Wait4
    Wow, I tried a bunch of things here.

    When running as PID 1, we are responsible for reaping zombies.
    Unfortunately, we can't do this in the simple/obvious way,
    because simply listening for SIGCHILD and reaping races
    with running cmd.Wait. We can't use a separate init process
    or double-init sketch, because then we lose our seccomp
    protection, and there's no particularly good way to extend it.

    Instead, (h/t to Philip asking a good question), observe
    that we are in a very controlled environment, and pretty much
    the only way to get zombies is via the bash tool.
    So we add reaping tied specifically to process groups started
    by the bash tool, with an explicit understanding of their lifecycle.

    Auto-installation of tools still creates zombies.
    We now know how to fix it, but it is rare, so who cares.