Hooks

run can execute a command of your choice around the update: --pre-exec before it, --post-exec after it. Use them to guard an update behind a check, snapshot state, regenerate lockfiles, or notify once versions moved.

clover run --pre-exec 'make snapshot' --post-exec 'make lock'

A failing pre-exec hook (any non-zero exit) aborts the run before any lookup or write. The post-exec hook runs once the update finished and produced a summary - even when some markers failed, since successful updates may already be on disk and still need the follow-up. It is skipped when the pre-exec hook aborted or the run errored before producing a summary. A failing post-exec hook makes clover run exit non-zero, and it never masks marker failures: both facts are reported.

A --dry-run previews without side effects, so it skips both hooks entirely.

Environment

Before the update a hook cannot know whether anything will change; after it, Clover does know. The distinction travels in environment variables, always all set, so a stale inherited value can never leak a false fact into a hook:

A post-exec hook that should act only on change branches on CLOVER_CHANGED:

clover run --post-exec '[ "$CLOVER_CHANGED" = true ] && make lock || true'

Shell

Hook commands run through /bin/sh -c (on Windows, cmd.exe /C), inheriting Clover’s working directory, environment, and standard streams. --exec-shell (or the CLOVER_HOOK_SHELL environment variable) swaps in another shell, invoked as <shell> -c <command> - the convention bash, zsh, fish, and pwsh all accept (cmd keeps its /C):

clover run --exec-shell fish --post-exec 'test "$CLOVER_CHANGED" = true; and make lock'