Honor ECC_DRY_RUN=1 in install and repair arg parsing (previously only --dry-run flag worked, so ecc --dry-run install/repair silently performed real writes). Make writeInstallState atomic via writeFileAtomic (O_EXCL staging, fsync, cleanup on failure, atomic rename preserving previous state). Add writeInstallState failure/concurrency/symlink regression tests and disposable-home CLI dry-run regression tests for both global and subcommand forms.
On Windows (native cmd/PowerShell), process.env.HOME is undefined.
Seven CLI entry points and two library files pass process.env.HOME
directly as homeDir without a cross-platform fallback, causing all
path resolutions to silently fail (resolving to "undefined/.claude/...").
Node.js os.homedir() correctly handles all platforms (HOME on Unix,
USERPROFILE on Windows, OS-level fallback). The project already uses
this pattern in scripts/lib/state-store/index.js and has a getHomeDir()
utility in scripts/lib/utils.js, but it was not applied consistently.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Lidang-Jiang <lidangjiang@gmail.com>
Geronimo