sbshadow --no: leave the hints alone

A preview ran mkhint -F all the same, so an sbpull or sbshadow preview
from sb-builder wrote hint files. --no now skips the sweep; --yes and the
interactive run still do it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 9 insertions, 5 deletions

diff --git a/AGENTS.md b/AGENTS.md
index 874558d..113c169 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -80,7 +80,7 @@ Pipeline, in order:
    package under `personal/` or `pentesting/` is `git rm`'d (shadow); any upstream package missing
    from HEAD and no longer carried in an overlay is restored with `git checkout current -- cat/pkg`
    (unshadow). A package is identified by a `$pkg/$pkg.SlackBuild` file. Match by directory
-   basename only, not content. Then it always runs `mkhint -F`.
+   basename only, not content. Then it runs `mkhint -F`, except on `--no`.
 
 `sbshadow` is also called by the `sbpull` bash function (`sbpull.bash`, sourced from root's `.bashrc` on the build VM) after a
 `git subtree pull`, so overlay changes are applied without regenerating the whole repo. It is the
diff --git a/README.md b/README.md
index e462c7e..731fafd 100644
--- a/README.md
+++ b/README.md
@@ -22,8 +22,8 @@ upstream tree), so the overlay version wins.
   carried in an overlay, and restores (unshadows) upstream packages no longer
   carried, from the pristine `current` branch. Asks once before changing
   anything, commits, then runs `mkhint -F` to regenerate phantom-dep hintfiles.
-  `--yes` applies without asking, `--no` only shows the plan (for
-  non-interactive callers such as sb-builder). `SBO_REPO` overrides the repo
+  `--yes` applies without asking, `--no` only shows the plan and skips
+  `mkhint -F` (for non-interactive callers such as sb-builder). `SBO_REPO` overrides the repo
   path.
 - `slackrepo_SBo-danix.conf`: the slackrepo config for this repo
   (`/etc/slackrepo/`). Site values (rsync target, Gotify URL and key) are not
diff --git a/sbshadow b/sbshadow
index 25cf923..7d20edd 100755
--- a/sbshadow
+++ b/sbshadow
@@ -77,9 +77,13 @@ else
 fi
 
 # ── regenerate phantom-dep hintfiles (mkhint owns them) ───────────────────────
-# Always runs: a subtree pull can change REQUIRES even with nothing to shadow.
+# Runs even with nothing to shadow (a subtree pull can change REQUIRES), but
+# not on --no: a preview leaves the hints alone too.
 # mkhint reads ~/.config/mkhint/phantom-deps; missing tool = harmless skip.
-if command -v mkhint >/dev/null 2>&1; then
+if [[ $answer == n ]]; then
+  echo
+  echo "sbshadow: preview, phantom-dep hintfiles not regenerated."
+elif command -v mkhint >/dev/null 2>&1; then
   echo
   echo "Regenerating phantom-dep hintfiles (mkhint -F)..."
   mkhint -F