[minor] `install skill` terminates with a libuv assertion (UV_HANDLE_CLOSING) on Windows — including on the already-installed no-op path

[tlemmonds]

Summary

Every kane-cli install skill invocation on Windows terminates with a libuv assertion:

Assertion failed: !(handle->flags & UV_HANDLE_CLOSING), file src\win\async.c, line 94

Exit code is 0 and the install result is correct, so nothing functionally breaks — but a clean no-op prints what reads as a crash, which is corrosive in CI logs and in front of an audience during a demo.

The important detail

It reproduces on the already-installed short-circuit path, where nothing is downloaded, nothing is extracted and nothing is written:

$ kane-cli install skill
{"type":"skill_install_result","status":"already-installed","version":"0.0.15","installed_targets":0}
Assertion failed: !(handle->flags & UV_HANDLE_CLOSING), file src\win\async.c, line 94

So this is not the tar/extraction path from #117 — it is process teardown. Something closes a libuv handle that is already closing.

Not a regression — and the line number is informative

Bisected across installs with the skill pinned at 0.0.15 throughout:

kane-cli	Runtime	Assertion
0.6.4	system Node v24.14.1	src\win\async.c, line 76
0.6.6	bundled kane-cli-node-win32	src\win\async.c, line 94
0.6.7	bundled kane-cli-node-win32	src\win\async.c, line 94

The line number tracks the runtime, not the CLI version — 0.6.4 predates the bundled Node runtime introduced in 0.6.6. That it reproduces identically under two different Node builds points at a genuine shutdown-ordering fault in the CLI rather than a quirk of one Node version.

Scope

Not observed on kane-cli whoami or kane-cli --version, so it is specific to install skill's shutdown sequence rather than a general CLI teardown problem.

Ask

Close (or unref) whatever async handle install skill leaves open before exit — most likely an update-check timer, an HTTP agent socket, or a progress/spinner handle that is torn down twice on the early-return path when the skill is already installed.

Environment

kane-cli 0.6.4 / 0.6.6 / 0.6.7 · skill 0.0.15 · Node v24.14.1 · Windows 11 Pro 26200 · Git Bash · account toddl