initial commit: docker test-build toolchain

Extracted from the .extras/ dir of the sbo-slackbuilds package repo, where it
grew from a throwaway helper into a standalone tool. Git history starts fresh;
the original 41-commit development log is preserved in HISTORY.md.

Contents: the test-build CLI (resolves a local SlackBuild's deps from a
configured SBo tree and builds it in a throwaway container, lints, caches deps),
the image-builder chain that produces the images it consumes, their pure-logic
self-checks, design specs/plans, an install.sh for ~/bin, and docs.

Licensed GPLv2-only.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 1579 insertions, 0 deletions

diff --git a/docs/plans/2026-07-13-docker-test-build.md b/docs/plans/2026-07-13-docker-test-build.md
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+# Docker test-build Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** A single bash script `.extras/test-build` that verifies an already-published SBo package still builds cleanly on `-current` or `15.0` inside a throwaway docker container, resolving and building its SBo deps from the local tree, caching built deps per image digest, and reporting per-package status + lint.
+
+**Architecture:** Host resolves the dep tree from the local SBo tree (logic ported from `sbo-batch-test`), applies current-vs-stable override rules, prints the build order and confirms, then runs one `docker run --rm` that builds deps (or installs them from a host cache) and the target, lints the target, and streams results back. The container is the disposable environment (no overlayfs). Images are built by a separate job and consumed by tag.
+
+**Tech Stack:** Bash, docker, Slackware `installpkg`/`makepkg`, `sbo-maintainer-tools` (`sbopkglint`). Self-check is plain bash (`test-logic.sh`), no framework.
+
+---
+
+## Reference source
+
+Port from `/home/danix/Programming/GIT/sbo-batch-tester/sbo-batch-test`. These
+functions are lifted with minimal change (they are pure or host-side):
+
+- `find_slackbuild_dir`, `category_of`, `pkg_key`, `read_requires`,
+  `version_of`, `installed_in_base`
+- resolver: `_resolve_visit`, `resolve_target`, globals `RESOLVED_ORDER`,
+  `UNMET`, `CYCLES`, `HAS_README`, `_vstate`
+- cache: `_cache_ver_of`, `cache_decision`, `cache_path`, `cache_store`,
+  `cache_label`
+- `depends_on_failed`, `print_summary`, `lint_pkg`, `init_color`
+- self-check patterns from
+  `/home/danix/Programming/GIT/sbo-batch-tester/test-logic.sh`
+
+What is NEW or CHANGED in this repo:
+
+- overlay lifecycle (`setup_overlay`/`teardown_overlay`/`cleanup_trap`) is
+  REMOVED. The container replaces it.
+- `build_one` is rewritten to run its build steps via `docker run` instead of
+  `chroot`.
+- image + tree selection by version (`--stable`).
+- override engine (drop / rename / fetch) applied to the resolved order.
+- cache namespaced by image digest.
+- config keys differ (see Task 2).
+
+## File Structure
+
+- Create: `/home/danix/Programming/GIT/sbo-slackbuilds/.extras/test-build`
+  (the script, executable)
+- Create:
+  `/home/danix/Programming/GIT/sbo-slackbuilds/.extras/test-build-config.example`
+  (config template)
+- Create:
+  `/home/danix/Programming/GIT/sbo-slackbuilds/.extras/overrides.example`
+  (override-rules template)
+- Create:
+  `/home/danix/Programming/GIT/sbo-slackbuilds/.extras/test-logic.sh`
+  (self-check)
+
+All work happens in `.extras/`. Run every command from the repo root
+`/home/danix/Programming/GIT/sbo-slackbuilds`.
+
+Note on committing: this repo has a pre-commit hook that runs `sbolint` on
+staged packages. `.extras/` files are not packages, but to be safe every
+commit in this plan uses `SBOLINT=no git commit ...`. Commits are GPG-signed
+automatically; do not disable signing.
+
+---
+
+## Task 1: Scaffold the script + smoke self-check
+
+**Files:**
+- Create: `.extras/test-build`
+- Create: `.extras/test-logic.sh`
+
+- [ ] **Step 1: Write the failing self-check**
+
+Create `.extras/test-logic.sh`:
+
+```bash
+#!/bin/bash
+#
+# Logic self-check for .extras/test-build. Covers the pure, host-side parts:
+# dependency resolution, override application, unknown-dep -> UNMET, cache
+# decisions, and BLOCKED-BY-DEP propagation. No docker.
+#
+# Run: bash .extras/test-logic.sh
+#
+set -uo pipefail
+
+SCRIPT="$(dirname "$0")/test-build"
+T=$(mktemp -d)
+BASE_DB=$(mktemp -d); mkdir -p "$BASE_DB"
+
+cleanup() { rm -rf "$T" "$BASE_DB"; }
+trap cleanup EXIT
+
+# Source the script without running main(). Sourcing re-runs the CONFIG block,
+# so set test vars AFTER the source.
+LIB=$(mktemp)
+sed '/^main "\$@"$/d' "$SCRIPT" > "$LIB"
+# shellcheck disable=SC1090
+source "$LIB" 2>/dev/null
+rm -f "$LIB"
+
+pass=0; fail=0
+ok()  { echo "  ok: $1"; ((pass++)); return 0; }
+bad() { echo "  FAIL: $1"; ((fail++)); return 0; }
+
+# Placeholder assertion so this file runs before any logic exists.
+ok "script sources without executing main"
+
+echo
+echo "$pass passed, $fail failed"
+[[ $fail -eq 0 ]] || exit 1
+echo "ALL LOGIC CHECKS PASS"
+```
+
+- [ ] **Step 2: Run it to verify it fails**
+
+Run: `bash .extras/test-logic.sh`
+Expected: FAIL. `$SCRIPT` does not exist yet, `sed`/`source` on a missing file
+errors, no "ALL LOGIC CHECKS PASS".
+
+- [ ] **Step 3: Write the minimal script skeleton**
+
+Create `.extras/test-build`:
+
+```bash
+#!/bin/bash
+#
+# test-build - verify an already-published SBo package still builds on a target
+# Slackware version inside a throwaway docker container. Resolves + builds its
+# SBo deps from the local tree, caches built deps per image digest, reports
+# per-package status and lints the target.
+#
+# Dependency-resolution, cache, and summary logic are adapted from sbo-batch-test
+# (github: danixland). The overlay chroot is replaced by a docker container: the
+# container IS the disposable environment, so no overlayfs.
+#
+# No em dashes in prose by author convention.
+
+# =============================================================================
+# CONFIG (do not edit here; real values live in the external config file)
+# =============================================================================
+SBO_TREE_CURRENT=""
+SBO_TREE_STABLE=""
+IMAGE_CURRENT=""
+IMAGE_STABLE=""
+LOG_ROOT="/var/log/sbo-test-build"
+PKG_CACHE=""
+
+TB_CONFIG="${TB_CONFIG:-$HOME/.config/sbo-testbuild/config}"
+if [[ -f "$TB_CONFIG" ]]; then
+  # shellcheck disable=SC1090
+  source "$TB_CONFIG"
+fi
+
+TB_OVERRIDES="${TB_OVERRIDES:-$HOME/.config/sbo-testbuild/overrides}"
+
+# =============================================================================
+set -uo pipefail
+# Not -e: a package build failing is a handled outcome, not a script crash.
+
+main() {
+  :
+}
+
+main "$@"
+```
+
+- [ ] **Step 4: Run the self-check to verify it passes**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS, ending `ALL LOGIC CHECKS PASS`.
+
+- [ ] **Step 5: Commit**
+
+```bash
+chmod +x .extras/test-build
+git add .extras/test-build .extras/test-logic.sh
+SBOLINT=no git commit -m 'test-build: scaffold script + self-check'
+```
+
+---
+
+## Task 2: Config, arg parsing, version selection
+
+**Files:**
+- Modify: `.extras/test-build`
+- Create: `.extras/test-build-config.example`
+- Test: `.extras/test-logic.sh`
+
+- [ ] **Step 1: Write the failing test**
+
+Append to `.extras/test-logic.sh` before the `--- result ---` block (the
+`echo; "$pass passed..."` lines at the end):
+
+```bash
+# --- version selection ------------------------------------------------------
+SBO_TREE_CURRENT="/trees/current"
+SBO_TREE_STABLE="/trees/stable"
+IMAGE_CURRENT="sbo-testbuild:current"
+IMAGE_STABLE="sbo-testbuild:15.0"
+
+VERSION_ID="current"; select_version_paths
+[[ "$ACTIVE_TREE" == "/trees/current" ]] && ok "current -> current tree" || bad "current tree wrong: [$ACTIVE_TREE]"
+[[ "$ACTIVE_IMAGE" == "sbo-testbuild:current" ]] && ok "current -> current image" || bad "current image wrong: [$ACTIVE_IMAGE]"
+
+VERSION_ID="15.0"; select_version_paths
+[[ "$ACTIVE_TREE" == "/trees/stable" ]] && ok "15.0 -> stable tree" || bad "stable tree wrong: [$ACTIVE_TREE]"
+[[ "$ACTIVE_IMAGE" == "sbo-testbuild:15.0" ]] && ok "15.0 -> stable image" || bad "stable image wrong: [$ACTIVE_IMAGE]"
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `bash .extras/test-logic.sh`
+Expected: FAIL, `select_version_paths: command not found`.
+
+- [ ] **Step 3: Implement config globals, flags, parse_args, select_version_paths**
+
+In `.extras/test-build`, replace the `main() { : }` line and everything up to
+`main "$@"` with the flags/globals and functions below (keep the CONFIG block
+above untouched):
+
+```bash
+# ---- flags / globals --------------------------------------------------------
+USE_COLOR=1        # --no-color or non-TTY disables
+DRY_RUN=0          # --dry-run: resolve + print order, do not build
+ASSUME_YES=0       # --yes: skip the confirm prompt (still prints the order)
+USE_CACHE=1        # --no-cache disables the dep cache for one run
+VERSION_ID="current"   # "current" | "15.0"; set by --stable
+TARGET_ARG=""
+
+ACTIVE_TREE=""     # selected SBo tree (by version)
+ACTIVE_IMAGE=""    # selected image tag (by version)
+RUN_DIR=""         # timestamped log dir for this run
+
+# Status tracking. Keyed by "category/prog". Parallel assoc arrays.
+declare -A ST_STATUS=()
+declare -A ST_REASON=()
+declare -A ST_TIME=()
+declare -A ST_README=()
+
+usage() {
+  cat <<'EOF'
+test-build - verify an SBo package builds on a target Slackware in docker
+
+USAGE:
+  test-build [OPTIONS] <program-name>
+
+OPTIONS:
+  -h, --help    This text.
+  --stable      Target Slackware 15.0 (image + tree). Default is -current.
+  --dry-run     Resolve, apply overrides, print the build order, do not build.
+  --yes         Skip the confirm prompt (the order is still printed first).
+  --no-cache    Rebuild all deps this run, ignore/refresh the cache.
+  --no-color    Disable ANSI color (auto-disabled when stdout is not a TTY).
+EOF
+}
+
+parse_args() {
+  while [[ $# -gt 0 ]]; do
+    case "$1" in
+      -h|--help) usage; exit 0 ;;
+      --stable|15.0) VERSION_ID="15.0"; shift ;;
+      --dry-run) DRY_RUN=1; shift ;;
+      --yes) ASSUME_YES=1; shift ;;
+      --no-cache) USE_CACHE=0; shift ;;
+      --no-color) USE_COLOR=0; shift ;;
+      -*) echo "Unknown option: $1" >&2; usage >&2; exit 2 ;;
+      *)
+        if [[ -n "$TARGET_ARG" ]]; then
+          echo "Only one target accepted (got '$TARGET_ARG' and '$1')." >&2
+          exit 2
+        fi
+        TARGET_ARG="$1"; shift ;;
+    esac
+  done
+  if [[ -z "$TARGET_ARG" ]]; then
+    echo "No target given." >&2; usage >&2; exit 2
+  fi
+}
+
+init_color() {
+  if [[ $USE_COLOR -eq 1 && -t 1 ]]; then
+    C_RED=$'\e[31m'; C_GRN=$'\e[32m'; C_YEL=$'\e[33m'; C_RST=$'\e[0m'
+  else
+    C_RED=""; C_GRN=""; C_YEL=""; C_RST=""
+  fi
+}
+
+# Map VERSION_ID to the active tree + image. No I/O, unit-testable.
+select_version_paths() {
+  if [[ "$VERSION_ID" == "15.0" ]]; then
+    ACTIVE_TREE="$SBO_TREE_STABLE"; ACTIVE_IMAGE="$IMAGE_STABLE"
+  else
+    ACTIVE_TREE="$SBO_TREE_CURRENT"; ACTIVE_IMAGE="$IMAGE_CURRENT"
+  fi
+}
+
+# require_config: the external config must exist and set the version's paths.
+require_config() {
+  if [[ ! -f "$TB_CONFIG" ]]; then
+    cat >&2 <<EOF
+No config file: $TB_CONFIG
+Copy the example and edit it:
+
+  mkdir -p "\$(dirname "$TB_CONFIG")"
+  cp .extras/test-build-config.example "$TB_CONFIG"
+  \${EDITOR:-vi} "$TB_CONFIG"
+EOF
+    exit 1
+  fi
+  select_version_paths
+  if [[ -z "$ACTIVE_TREE" || -z "$ACTIVE_IMAGE" ]]; then
+    echo "Config $TB_CONFIG is missing the tree/image for version '$VERSION_ID'." >&2
+    exit 1
+  fi
+  if [[ ! -d "$ACTIVE_TREE" ]]; then
+    echo "SBo tree for '$VERSION_ID' does not exist: $ACTIVE_TREE" >&2
+    exit 1
+  fi
+}
+
+main() {
+  parse_args "$@"
+  init_color
+  require_config
+}
+
+main "$@"
+```
+
+- [ ] **Step 4: Run test to verify it passes**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS (the new version-selection checks included).
+
+- [ ] **Step 5: Write the config example**
+
+Create `.extras/test-build-config.example`:
+
+```bash
+# test-build config. Copy to ~/.config/sbo-testbuild/config and edit.
+# Override the path with the TB_CONFIG environment variable.
+
+# Local SBo trees, one per target Slackware version.
+SBO_TREE_CURRENT="/home/danix/SBo/current"
+SBO_TREE_STABLE="/home/danix/SBo/15.0"
+
+# Ready image tags (built by a separate job, consumed here by tag).
+IMAGE_CURRENT="sbo-testbuild:current"
+IMAGE_STABLE="sbo-testbuild:15.0"
+
+# Where per-run logs land.
+LOG_ROOT="/home/danix/.cache/sbo-test-build"
+
+# Dependency package cache (host dir). Empty disables caching.
+# Namespaced internally by image digest, so it self-invalidates on image update
+# and keeps current vs 15.0 separate.
+PKG_CACHE="/home/danix/.cache/sbo-test-build/pkgcache"
+```
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add .extras/test-build .extras/test-build-config.example .extras/test-logic.sh
+SBOLINT=no git commit -m 'test-build: config, arg parsing, version selection'
+```
+
+---
+
+## Task 3: Port the SBo-tree lookup + resolver + self-check
+
+**Files:**
+- Modify: `.extras/test-build`
+- Test: `.extras/test-logic.sh`
+
+- [ ] **Step 1: Write the failing test**
+
+Append to `.extras/test-logic.sh` before the result block:
+
+```bash
+# --- resolution -------------------------------------------------------------
+# Fake SBo tree under one category. mk <prog> "<REQUIRES>".
+mk() { mkdir -p "$T/cat/$1"; echo "REQUIRES=\"$2\"" > "$T/cat/$1/$1.info"; }
+mk c ""
+mk b "c"
+mk a "b %README%"
+mk d "nonexistentpkg"
+mk e "f"
+mk f "e"
+mk g "b"
+
+SBO_TREE_ROOTS=("$T")   # resolver reads this global (set by select in real runs)
+
+resolve_target "$T/cat/a"
+order=""; for x in "${RESOLVED_ORDER[@]}"; do order+="$(basename "$x") "; done
+order="${order% }"
+[[ "$order" == "c b a" ]] && ok "topo order c b a" || bad "topo order, got: [$order]"
+[[ "${HAS_README[$T/cat/a]:-}" == "1" ]] && ok "%README% recorded" || bad "%README% not recorded"
+[[ ${#UNMET[@]} -eq 0 ]] && ok "no false unmet" || bad "unexpected unmet"
+
+resolve_target "$T/cat/d"
+[[ ${#UNMET[@]} -eq 1 ]] && ok "unmet-dep caught" || bad "unmet-dep missed"
+
+resolve_target "$T/cat/e"
+[[ ${#CYCLES[@]} -ge 1 ]] && ok "cycle caught" || bad "cycle missed"
+```
+
+Note: the base-installed check (`installed_in_base`) is exercised in real runs
+against the container, not here. In the self-check `BASE_DB` is empty, so a dep
+that is neither in the tree nor a known override reads as UNMET (which is the
+behavior we test with `d`).
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `bash .extras/test-logic.sh`
+Expected: FAIL, `resolve_target: command not found`.
+
+- [ ] **Step 3: Implement lookup + resolver (ported)**
+
+Add to `.extras/test-build` above `main()`:
+
+```bash
+# =============================================================================
+# SBo tree lookup
+# =============================================================================
+# In this tool there is one active tree per run, but the resolver reads an array
+# named SBO_TREE_ROOTS so the ported logic and its self-check match sbo-batch-test.
+# main() sets SBO_TREE_ROOTS=("$ACTIVE_TREE") after require_config.
+declare -a SBO_TREE_ROOTS=()
+
+find_slackbuild_dir() {
+  local prog="$1" root d
+  for root in "${SBO_TREE_ROOTS[@]}"; do
+    [[ -d "$root" ]] || continue
+    for d in "$root"/*/"$prog"; do
+      if [[ -d "$d" && -f "$d/$prog.info" ]]; then
+        echo "$d"; return 0
+      fi
+    done
+  done
+  return 1
+}
+
+category_of() { basename "$(dirname "$1")"; }
+pkg_key() { echo "$(category_of "$1")/$(basename "$1")"; }
+
+read_requires() {
+  local info="$1"
+  # shellcheck disable=SC1090
+  ( set +u; source "$info"; echo "${REQUIRES:-}" )
+}
+
+version_of() {
+  local dir="$1"
+  local info="$dir/$(basename "$dir").info"
+  [[ -f "$info" ]] || return
+  local v; v="$(grep -m1 '^VERSION=' "$info" | cut -d'"' -f2)"
+  echo "$v"
+}
+
+# =============================================================================
+# DEPENDENCY RESOLUTION (topo sort + cycle detection, LOCAL tree only)
+# =============================================================================
+declare -a RESOLVED_ORDER=()
+declare -A UNMET=()
+declare -a CYCLES=()
+declare -A HAS_README=()
+declare -A _vstate=()
+
+# Is a prog already present in the container base? Overridden at build time to
+# consult the image; in resolution we treat "in base" as a callback so the pure
+# topo logic stays testable. Default: not in base (self-check has no base db).
+installed_in_base() { return 1; }
+
+_resolve_visit() {
+  local dir="$1" parent="$2"
+  local key; key="$(basename "$dir")"
+
+  if [[ "${_vstate[$dir]:-}" == "1" ]]; then return 0; fi
+  if [[ "${_vstate[$dir]:-}" == "0" ]]; then
+    CYCLES+=("cycle involving $key (pulled in via $parent)")
+    return 1
+  fi
+  _vstate["$dir"]=0
+
+  local info="$dir/$(basename "$dir").info"
+  local req tok depdir rc=0
+  req="$(read_requires "$info")"
+  for tok in $req; do
+    if [[ "$tok" == "%README%" ]]; then
+      HAS_README["$dir"]=1
+      continue
+    fi
+    if depdir="$(find_slackbuild_dir "$tok")"; then
+      _resolve_visit "$depdir" "$key" || rc=1
+    elif installed_in_base "$tok"; then
+      :
+    else
+      UNMET["$tok"]="needed by $key"
+      rc=1
+    fi
+  done
+
+  _vstate["$dir"]=1
+  RESOLVED_ORDER+=("$dir")
+  return $rc
+}
+
+resolve_target() {
+  local dir="$1"
+  RESOLVED_ORDER=()
+  CYCLES=()
+  UNMET=()
+  _vstate=()
+  _resolve_visit "$dir" "(top)"
+}
+```
+
+Update `main()` to set the resolver's tree array after `require_config`:
+
+```bash
+main() {
+  parse_args "$@"
+  init_color
+  require_config
+  SBO_TREE_ROOTS=("$ACTIVE_TREE")
+}
+```
+
+- [ ] **Step 4: Run test to verify it passes**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS (topo order, %README%, unmet, cycle checks green).
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add .extras/test-build .extras/test-logic.sh
+SBOLINT=no git commit -m 'test-build: port SBo lookup + dependency resolver'
+```
+
+---
+
+## Task 4: Override engine (drop / rename / fetch) + UNMET stop
+
+**Files:**
+- Modify: `.extras/test-build`
+- Create: `.extras/overrides.example`
+- Test: `.extras/test-logic.sh`
+
+The override file encodes current-vs-stable deltas. It is applied ONLY when
+`VERSION_ID == current` (15.0 is the SBo baseline). Rules:
+
+- `drop:   <prog>`            remove from the build order (already in -current base)
+- `rename: <old> -> <new>`    rewrite the dep name before it is looked up
+- `fetch:  <prog>`            mark this dep to come from sbopkg in-container, not the local tree
+
+- [ ] **Step 1: Write the failing test**
+
+Append to `.extras/test-logic.sh` before the result block:
+
+```bash
+# --- overrides --------------------------------------------------------------
+OV=$(mktemp)
+cat > "$OV" <<'EOF'
+# comment ignored
+drop:   dropme
+rename: oldname -> newname
+fetch:  fetchme
+EOF
+TB_OVERRIDES="$OV"
+load_overrides
+
+[[ "${OV_DROP[dropme]:-}" == "1" ]] && ok "override drop parsed" || bad "drop not parsed"
+[[ "${OV_RENAME[oldname]:-}" == "newname" ]] && ok "override rename parsed" || bad "rename not parsed"
+[[ "${OV_FETCH[fetchme]:-}" == "1" ]] && ok "override fetch parsed" || bad "fetch not parsed"
+
+# rename maps a token
+[[ "$(apply_rename oldname)" == "newname" ]] && ok "apply_rename maps" || bad "apply_rename wrong: [$(apply_rename oldname)]"
+[[ "$(apply_rename untouched)" == "untouched" ]] && ok "apply_rename passthrough" || bad "apply_rename mangled untouched"
+
+# drop filters the order (build a fake order of dirs; dropme is removed)
+mk dropme ""
+mk keepme ""
+RESOLVED_ORDER=("$T/cat/dropme" "$T/cat/keepme")
+apply_overrides_to_order
+kept=""; for x in "${RESOLVED_ORDER[@]}"; do kept+="$(basename "$x") "; done
+kept="${kept% }"
+[[ "$kept" == "keepme" ]] && ok "drop removes from order" || bad "drop failed, order=[$kept]"
+rm -f "$OV"
+
+# overrides only apply on current; on 15.0 they are a no-op
+VERSION_ID="15.0"
+TB_OVERRIDES="$OV"   # file gone; must not error, must clear maps
+load_overrides
+[[ ${#OV_DROP[@]} -eq 0 ]] && ok "overrides inert on 15.0" || bad "overrides applied on 15.0"
+VERSION_ID="current"
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `bash .extras/test-logic.sh`
+Expected: FAIL, `load_overrides: command not found`.
+
+- [ ] **Step 3: Implement the override engine**
+
+Add to `.extras/test-build` above `main()`:
+
+```bash
+# =============================================================================
+# current-vs-stable overrides. Parsed from $TB_OVERRIDES. Applied only when
+# targeting -current (15.0 is the SBo baseline, no deltas).
+# =============================================================================
+declare -A OV_DROP=()      # prog -> 1
+declare -A OV_RENAME=()    # old  -> new
+declare -A OV_FETCH=()     # prog -> 1
+
+load_overrides() {
+  OV_DROP=(); OV_RENAME=(); OV_FETCH=()
+  # 15.0 is the baseline: no overrides.
+  [[ "$VERSION_ID" == "15.0" ]] && return
+  [[ -f "$TB_OVERRIDES" ]] || return
+  local line kind rest
+  while IFS= read -r line; do
+    line="${line%%#*}"                       # strip comments
+    line="${line#"${line%%[![:space:]]*}"}"  # ltrim
+    [[ -z "$line" ]] && continue
+    kind="${line%%:*}"; rest="${line#*:}"
+    kind="${kind//[[:space:]]/}"
+    rest="${rest#"${rest%%[![:space:]]*}"}"  # ltrim value
+    case "$kind" in
+      drop)   OV_DROP["${rest//[[:space:]]/}"]=1 ;;
+      fetch)  OV_FETCH["${rest//[[:space:]]/}"]=1 ;;
+      rename)
+        # rest is "old -> new"
+        local old new
+        old="${rest%%->*}"; new="${rest##*->}"
+        old="${old//[[:space:]]/}"; new="${new//[[:space:]]/}"
+        [[ -n "$old" && -n "$new" ]] && OV_RENAME["$old"]="$new" ;;
+      *) echo "WARN: unknown override rule: $line" >&2 ;;
+    esac
+  done < "$TB_OVERRIDES"
+}
+
+# Map a dep token through rename rules (identity if no rule).
+apply_rename() {
+  local tok="$1"
+  echo "${OV_RENAME[$tok]:-$tok}"
+}
+
+# Remove dropped packages from RESOLVED_ORDER in place.
+apply_overrides_to_order() {
+  local d prog keep=()
+  for d in "${RESOLVED_ORDER[@]}"; do
+    prog="$(basename "$d")"
+    [[ "${OV_DROP[$prog]:-}" == "1" ]] && continue
+    keep+=("$d")
+  done
+  RESOLVED_ORDER=("${keep[@]:-}")
+}
+```
+
+Wire `apply_rename` into the resolver so renamed deps look up under the new
+name. In `_resolve_visit`, change the dep-lookup line:
+
+```bash
+  for tok in $req; do
+    if [[ "$tok" == "%README%" ]]; then
+      HAS_README["$dir"]=1
+      continue
+    fi
+    tok="$(apply_rename "$tok")"          # <-- add this line
+    if [[ "${OV_FETCH[$tok]:-}" == "1" ]]; then
+      FETCH_DEPS["$tok"]=1                 # satisfied via sbopkg at build time
+      continue
+    fi
+    if depdir="$(find_slackbuild_dir "$tok")"; then
+      _resolve_visit "$depdir" "$key" || rc=1
+    elif installed_in_base "$tok"; then
+      :
+    else
+      UNMET["$tok"]="needed by $key"
+      rc=1
+    fi
+  done
+```
+
+Add the `FETCH_DEPS` global with the other resolver globals:
+
+```bash
+declare -A FETCH_DEPS=()   # prog -> 1: resolve via sbopkg in-container
+```
+
+And reset it in `resolve_target`:
+
+```bash
+resolve_target() {
+  local dir="$1"
+  RESOLVED_ORDER=()
+  CYCLES=()
+  UNMET=()
+  FETCH_DEPS=()
+  _vstate=()
+  _resolve_visit "$dir" "(top)"
+}
+```
+
+Load overrides in `main()` (before any resolve happens, after tree setup):
+
+```bash
+main() {
+  parse_args "$@"
+  init_color
+  require_config
+  SBO_TREE_ROOTS=("$ACTIVE_TREE")
+  load_overrides
+}
+```
+
+- [ ] **Step 4: Run test to verify it passes**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS (all override checks green).
+
+- [ ] **Step 5: Write the overrides example**
+
+Create `.extras/overrides.example`:
+
+```
+# current-vs-stable dep overrides for test-build.
+# Copy to ~/.config/sbo-testbuild/overrides and edit. Applied only when
+# targeting -current (15.0 is the SBo baseline). One rule per line.
+#
+#   drop:   <prog>            dep is in 15.0 but already in the -current base
+#   rename: <old> -> <new>    dep was renamed on -current
+#   fetch:  <prog>            dep was removed from the -current tree; pull via sbopkg
+#
+# Start light: add rules only when a real package needs them.
+
+# drop:   rust
+# rename: python3-foo -> foo
+# fetch:  somelib
+```
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add .extras/test-build .extras/overrides.example .extras/test-logic.sh
+SBOLINT=no git commit -m 'test-build: current-vs-stable override engine'
+```
+
+---
+
+## Task 5: Port the dep cache, namespaced by image digest
+
+**Files:**
+- Modify: `.extras/test-build`
+- Test: `.extras/test-logic.sh`
+
+The cache is the ported sbo-batch-test cache with one change: the cache root
+seen by `cache_*` is `$PKG_CACHE/<image-digest>`, computed once per run. A new
+digest gives a fresh namespace (old deps ignored), which is the invalidation.
+
+- [ ] **Step 1: Write the failing test**
+
+Append to `.extras/test-logic.sh` before the result block:
+
+```bash
+# --- cache ------------------------------------------------------------------
+PKG_CACHE=$(mktemp -d)
+CACHE_ROOT="$PKG_CACHE/sha256-deadbeef"   # simulate a resolved digest namespace
+mkc() { mkdir -p "$CACHE_ROOT/$1/$2"; : > "$CACHE_ROOT/$1/$2/$3"; }
+
+mkc net libfoo "libfoo-1.1-x86_64-1_danix.txz"
+[[ "$(cache_decision net libfoo 1.1)" == "cached" ]] && ok "cache hit on version match" || bad "cache_decision got [$(cache_decision net libfoo 1.1)]"
+[[ "$(cache_decision net libfoo 1.2)" == "bump:1.1:1.2" ]] && ok "cache bump reported" || bad "cache bump got [$(cache_decision net libfoo 1.2)]"
+[[ "$(cache_decision net libbar 1.0)" == "new" ]] && ok "cache new for absent" || bad "cache new got [$(cache_decision net libbar 1.0)]"
+
+hit="$(cache_path net libfoo 1.1)"
+[[ "$hit" == "$CACHE_ROOT/net/libfoo/libfoo-1.1-x86_64-1_danix.txz" ]] && ok "cache_path returns hit" || bad "cache_path got [$hit]"
+[[ -z "$(cache_path net libfoo 9.9)" ]] && ok "cache_path empty on miss" || bad "cache_path not empty on miss"
+
+srctmp=$(mktemp -d); : > "$srctmp/libfoo-1.2-x86_64-1_danix.txz"
+cache_store net libfoo "$srctmp/libfoo-1.2-x86_64-1_danix.txz"
+count=$(find "$CACHE_ROOT/net/libfoo" -name '*.t?z' | wc -l)
+[[ "$count" -eq 1 ]] && ok "cache_store evicts to one file" || bad "cache_store left $count files"
+[[ -e "$CACHE_ROOT/net/libfoo/libfoo-1.2-x86_64-1_danix.txz" ]] && ok "cache_store stored new file" || bad "cache_store did not store"
+rm -rf "$srctmp"
+
+# disabled cache -> new
+CACHE_ROOT_SAVE="$CACHE_ROOT"; USE_CACHE=0
+[[ "$(cache_decision net libfoo 1.2)" == "new" ]] && ok "--no-cache disables (new)" || bad "disabled cache got [$(cache_decision net libfoo 1.2)]"
+USE_CACHE=1; CACHE_ROOT="$CACHE_ROOT_SAVE"
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `bash .extras/test-logic.sh`
+Expected: FAIL, `cache_decision: command not found`.
+
+- [ ] **Step 3: Implement the cache (ported, keyed on CACHE_ROOT + USE_CACHE)**
+
+Add to `.extras/test-build` above `main()`:
+
+```bash
+# =============================================================================
+# Dependency cache. Layout: $CACHE_ROOT/<cat>/<prog>/<prog>-<ver>-...txz where
+# CACHE_ROOT = $PKG_CACHE/<image-digest> (set per run by resolve_cache_root).
+# Key is prog+version. --no-cache (USE_CACHE=0) or empty PKG_CACHE disables.
+# =============================================================================
+CACHE_ROOT=""   # set by resolve_cache_root once the image digest is known
+
+# True when the cache is usable this run.
+_cache_on() { [[ $USE_CACHE -eq 1 && -n "$PKG_CACHE" && -n "$CACHE_ROOT" ]]; }
+
+_cache_ver_of() {
+  local prog="$1" base="$2"
+  base="${base#"$prog"-}"
+  echo "${base%%-*}"
+}
+
+# cache_decision <cat> <prog> <version> -> cached | bump:OLD:NEW | new
+cache_decision() {
+  local cat="$1" prog="$2" version="$3"
+  _cache_on || { echo new; return; }
+  local dir="$CACHE_ROOT/$cat/$prog"
+  local f newest=""
+  for f in "$dir/$prog"-*.t?z; do
+    [[ -e "$f" ]] || continue
+    [[ -z "$newest" || "$f" -nt "$newest" ]] && newest="$f"
+  done
+  [[ -z "$newest" ]] && { echo new; return; }
+  local have; have="$(_cache_ver_of "$prog" "$(basename "$newest")")"
+  if [[ "$have" == "$version" ]]; then echo cached; else echo "bump:$have:$version"; fi
+}
+
+cache_path() {
+  local cat="$1" prog="$2" version="$3"
+  _cache_on || return
+  local dir="$CACHE_ROOT/$cat/$prog"
+  local f newest=""
+  for f in "$dir/$prog"-*.t?z; do
+    [[ -e "$f" ]] || continue
+    [[ -z "$newest" || "$f" -nt "$newest" ]] && newest="$f"
+  done
+  [[ -z "$newest" ]] && return
+  [[ "$(_cache_ver_of "$prog" "$(basename "$newest")")" == "$version" ]] && echo "$newest"
+}
+
+cache_store() {
+  local cat="$1" prog="$2" src="$3"
+  _cache_on || return
+  local dir="$CACHE_ROOT/$cat/$prog"
+  mkdir -p "$dir"
+  rm -f "$dir"/*.t?z
+  cp -a "$src" "$dir/"
+}
+
+cache_label() {
+  local dir="$1" is_target="$2"
+  local cat prog ver dec
+  cat="$(category_of "$dir")"; prog="$(basename "$dir")"; ver="$(version_of "$dir")"
+  dec="$(cache_decision "$cat" "$prog" "$ver")"
+  local label
+  case "$dec" in
+    cached)   label="cached ($ver)" ;;
+    bump:*)   label="rebuild: ${dec#bump:}"; label="${label/:/ -> }" ;;
+    *)        label="build (new)" ;;
+  esac
+  if [[ "$is_target" == "1" ]]; then
+    case "$dec" in
+      cached) label="build (cached $ver, rebuilt as target)" ;;
+    esac
+    echo "target, $label"
+  else
+    echo "$label"
+  fi
+}
+
+# Compute CACHE_ROOT from the image's digest. Falls back to the tag if the
+# digest cannot be read (still isolates per image reference).
+resolve_cache_root() {
+  [[ -z "$PKG_CACHE" ]] && { CACHE_ROOT=""; return; }
+  local digest
+  digest="$(docker image inspect --format '{{index .Id}}' "$ACTIVE_IMAGE" 2>/dev/null)"
+  [[ -z "$digest" ]] && digest="tag-${ACTIVE_IMAGE//[^a-zA-Z0-9._-]/_}"
+  digest="${digest//[^a-zA-Z0-9._-]/_}"
+  CACHE_ROOT="$PKG_CACHE/$digest"
+  mkdir -p "$CACHE_ROOT"
+}
+```
+
+- [ ] **Step 4: Run test to verify it passes**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS (all cache checks green).
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add .extras/test-build .extras/test-logic.sh
+SBOLINT=no git commit -m 'test-build: port dep cache, namespaced by image digest'
+```
+
+---
+
+## Task 6: BLOCKED-BY-DEP propagation (ported)
+
+**Files:**
+- Modify: `.extras/test-build`
+- Test: `.extras/test-logic.sh`
+
+- [ ] **Step 1: Write the failing test**
+
+Append to `.extras/test-logic.sh` before the result block:
+
+```bash
+# --- BLOCKED-BY-DEP (depends_on_failed) -------------------------------------
+dead=(b)
+if depends_on_failed "$T/cat/g" dead; then ok "g blocked when b dead"; else bad "g should block on b"; fi
+if depends_on_failed "$T/cat/a" dead; then ok "a blocked when b dead (direct)"; else bad "a should block on b"; fi
+
+dead=(c)
+if depends_on_failed "$T/cat/a" dead; then bad "a wrongly blocked on c"; else ok "a not directly blocked by c"; fi
+if depends_on_failed "$T/cat/b" dead; then ok "b blocked when c dead"; else bad "b should block on c"; fi
+
+dead=()
+if depends_on_failed "$T/cat/a" dead; then bad "a blocked with empty dead"; else ok "no block when nothing dead"; fi
+
+dead=("%README%")
+if depends_on_failed "$T/cat/a" dead; then bad "%README% treated as dep"; else ok "%README% not treated as dep"; fi
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `bash .extras/test-logic.sh`
+Expected: FAIL, `depends_on_failed: command not found`.
+
+- [ ] **Step 3: Implement depends_on_failed (ported)**
+
+Add to `.extras/test-build` above `main()`:
+
+```bash
+# Does SlackBuild dir $1 directly require any prog in the dead list (nameref $2)?
+# Direct-requires check only; transitive blocking works because run_target
+# iterates in topo order, propagating a failure one hop per package.
+depends_on_failed() {
+  local dir="$1"; local -n failed="$2"
+  local info="$dir/$(basename "$dir").info"
+  local req tok f
+  req="$(read_requires "$info")"
+  for tok in $req; do
+    [[ "$tok" == "%README%" ]] && continue
+    for f in "${failed[@]:-}"; do
+      [[ "$tok" == "$f" ]] && return 0
+    done
+  done
+  return 1
+}
+```
+
+- [ ] **Step 4: Run test to verify it passes**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add .extras/test-build .extras/test-logic.sh
+SBOLINT=no git commit -m 'test-build: port BLOCKED-BY-DEP propagation'
+```
+
+---
+
+## Task 7: The container build step (build_one via docker)
+
+**Files:**
+- Modify: `.extras/test-build`
+
+No self-check here (docker/build is out of the pure-logic reach, same boundary
+as sbo-batch-test). Verified by a real run in Task 10.
+
+- [ ] **Step 1: Implement build_one + lint_pkg**
+
+Add to `.extras/test-build` above `main()`.
+
+`lint_pkg` is ported verbatim:
+
+```bash
+# lint_pkg <txz> <logf> -> run sbopkglint on a built package. Host-side, target
+# only, fail-soft (skip if absent, never change SUCCESS).
+lint_pkg() {
+  local txz="$1" logf="$2"
+  if ! command -v sbopkglint >/dev/null 2>&1; then
+    echo "  sbopkglint not installed on host, skipping lint"
+    return 0
+  fi
+  echo "  sbopkglint $(basename "$txz") ..."
+  echo "===== sbopkglint: $(basename "$txz") =====" >> "$logf"
+  local out rc
+  out="$(sbopkglint "$txz" 2>&1)"; rc=$?
+  printf '%s\n' "$out" >> "$logf"
+  if [[ $rc -eq 0 ]]; then
+    echo "  lint: ${C_GRN}clean${C_RST}"
+  else
+    echo "  lint: ${C_RED}findings${C_RST} (see $(basename "$logf")):"
+    printf '%s\n' "$out" | sed 's/^/    /'
+  fi
+}
+```
+
+`build_one` runs the same download/md5/build/installpkg steps as sbo-batch-test,
+but inside a container via `docker run` instead of `chroot`. The container gets:
+the SlackBuild dir mounted read-only, a work dir for output, and (for deps) the
+cached .txz mounted in. `sbopkglint` runs host-side on the copied-out package.
+
+```bash
+# build_one <slackbuild-dir> <is_target 0|1> [container-name]
+# Runs the build in a throwaway container. Sets ST_STATUS/ST_REASON/ST_TIME.
+# Successful builds copy their package to a host workdir; deps are cached and
+# the target is linted. Returns 0 on SUCCESS/CACHED, 1 otherwise.
+build_one() {
+  local dir="$1" is_target="${2:-0}"
+  local prog cat key
+  prog="$(basename "$dir")"; cat="$(category_of "$dir")"; key="$cat/$prog"
+  local logf="$RUN_DIR/${cat}_${prog}.log"
+  local start; start=$(date +%s)
+  local version; version="$(version_of "$dir")"
+
+  [[ "${HAS_README[$dir]:-}" == "1" ]] && ST_README["$key"]=1
+
+  # Dep with a version-matching cached package: installpkg it into the shared
+  # dep-package dir; no build. The target never takes this path.
+  if [[ "$is_target" != "1" ]]; then
+    local cached; cached="$(cache_path "$cat" "$prog" "$version")"
+    if [[ -n "$cached" ]]; then
+      cp -a "$cached" "$DEPS_DIR/"
+      {
+        echo "===== test-build: $prog (from cache) ====="
+        echo "cached package: $(basename "$cached")"
+      } >> "$logf"
+      ST_TIME["$key"]=$(( $(date +%s) - start ))
+      ST_STATUS["$key"]="CACHED"
+      return 0
+    fi
+  fi
+
+  # Build in a container. Mounts:
+  #   $dir           -> /sbo/pkg    (ro, the SlackBuild)
+  #   $DEPS_DIR      -> /sbo/deps   (rw, already-built dep .txz to installpkg first)
+  #   $BUILD_OUT     -> /sbo/out    (rw, where the built package is copied out)
+  # The in-container script installs any deps present, then builds the target,
+  # writes a status token to /sbo/out/$prog.status, and copies the package out.
+  local statf="$BUILD_OUT/$prog.status"
+  rm -f "$statf"
+
+  # fetch deps (removed from -current tree): let the container's sbopkg build
+  # them first. FETCH_DEPS is the set collected during resolution.
+  local fetch_list=""
+  local fp
+  for fp in "${!FETCH_DEPS[@]}"; do fetch_list+="$fp "; done
+
+  docker run --rm \
+    -v "$dir":/sbo/pkg:ro \
+    -v "$DEPS_DIR":/sbo/deps \
+    -v "$BUILD_OUT":/sbo/out \
+    -e PROG="$prog" \
+    -e FETCH_LIST="$fetch_list" \
+    "$ACTIVE_IMAGE" /bin/bash -s >>"$logf" 2>&1 <<'CONTAINER_EOF'
+set -uo pipefail
+prog="$PROG"
+statf="/sbo/out/$prog.status"
+
+# 0. install already-built dependency packages (order guaranteed by the host).
+for d in /sbo/deps/*.t?z; do
+  [[ -e "$d" ]] || continue
+  installpkg --terse "$d" || { echo "INSTALL-FAILED (dep $d)"; echo INSTALL-FAILED > "$statf"; exit 1; }
+done
+
+# 0b. fetch-from-SBo deps via sbopkg (removed from the -current tree).
+for f in $FETCH_LIST; do
+  echo "sbopkg-building fetch dep: $f"
+  sbopkg -B -i "$f" || { echo "BUILD-FAILED (fetch dep $f)"; echo BUILD-FAILED > "$statf"; exit 1; }
+done
+
+# copy the SlackBuild out of the read-only mount so it can write there.
+cp -a /sbo/pkg /sbo/build
+cd /sbo/build || { echo BUILD-FAILED > "$statf"; exit 1; }
+. ./"$prog".info
+
+export OUTPUT=/sbo/out
+mkdir -p "$OUTPUT"
+
+echo "===== test-build: $prog ====="
+echo "PRGNAM=${PRGNAM:-$prog} VERSION=${VERSION:-?} BUILD=${BUILD:-?} TAG=${TAG:-?}"
+echo "uname -m: $(uname -m)   OUTPUT=$OUTPUT"
+echo "REQUIRES=${REQUIRES:-}"
+echo "================================="
+
+if [ "$(uname -m)" = "x86_64" ] && [ -n "${DOWNLOAD_x86_64:-}" ] && [ "${DOWNLOAD_x86_64}" != "UNSUPPORTED" ] && [ "${DOWNLOAD_x86_64}" != "UNTESTED" ]; then
+  DL="$DOWNLOAD_x86_64"; MD="$MD5SUM_x86_64"
+else
+  DL="$DOWNLOAD"; MD="$MD5SUM"
+fi
+
+for u in $DL; do
+  wget -c --tries=3 "$u" || { echo DOWNLOAD-FAILED > "$statf"; exit 1; }
+done
+
+set -- $MD
+for u in $DL; do
+  f="$(basename "$u")"
+  want="$1"; shift
+  got="$(md5sum "$f" | cut -d' ' -f1)"
+  if [ "$got" != "$want" ]; then
+    echo "MD5 mismatch on $f: want $want got $got"
+    echo MD5-MISMATCH > "$statf"; exit 1
+  fi
+done
+
+chmod +x ./"$prog".SlackBuild
+if ! ./"$prog".SlackBuild; then
+  echo BUILD-FAILED > "$statf"; exit 1
+fi
+
+pkg="$(ls -t "$OUTPUT"/"$prog"-*.t?z 2>/dev/null | head -n1)"
+if [ -z "$pkg" ]; then
+  echo "No package produced in $OUTPUT"
+  echo BUILD-FAILED > "$statf"; exit 1
+fi
+if ! installpkg --terse "$pkg"; then
+  echo INSTALL-FAILED > "$statf"; exit 1
+fi
+echo "===== installed files: $(basename "$pkg") ====="
+pkgname="$(basename "$pkg")"; pkgname="${pkgname%.t?z}"
+cat "/var/log/packages/$pkgname" 2>/dev/null || echo "(package db entry not found)"
+echo "================================="
+echo SUCCESS > "$statf"
+CONTAINER_EOF
+
+  local status="BUILD-FAILED"
+  [[ -f "$statf" ]] && status="$(cat "$statf")"
+  ST_TIME["$key"]=$(( $(date +%s) - start ))
+  ST_STATUS["$key"]="$status"
+
+  if [[ "$status" == "SUCCESS" ]]; then
+    # locate the built package copied to the host workdir
+    local built newest=""
+    for built in "$BUILD_OUT/${prog}"-*.t?z; do
+      [[ -e "$built" ]] || continue
+      [[ -z "$newest" || "$built" -nt "$newest" ]] && newest="$built"
+    done
+    if [[ -n "$newest" ]]; then
+      if [[ "$is_target" != "1" ]]; then
+        cache_store "$cat" "$prog" "$newest"
+        # make the dep available to later builds in this run
+        cp -a "$newest" "$DEPS_DIR/"
+      else
+        lint_pkg "$newest" "$logf"
+      fi
+    fi
+    return 0
+  fi
+  ST_REASON["$key"]="see $(basename "$logf")"
+  return 1
+}
+```
+
+- [ ] **Step 2: Sanity-check bash syntax**
+
+Run: `bash -n .extras/test-build`
+Expected: no output (syntax OK).
+
+- [ ] **Step 3: Run the self-check still passes (no regression)**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS (build_one is not exercised, but sourcing must not break).
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add .extras/test-build
+SBOLINT=no git commit -m 'test-build: container build step (build_one via docker)'
+```
+
+---
+
+## Task 8: run_target orchestration + summary
+
+**Files:**
+- Modify: `.extras/test-build`
+
+- [ ] **Step 1: Implement run_target + print_summary + confirm**
+
+Add to `.extras/test-build` above `main()`. `print_summary` is ported verbatim
+(status set is the same). `run_target` replaces the overlay lifecycle with the
+per-run docker workdirs and adds the printed-order + Y/n confirm.
+
+```bash
+# confirm_order: print the resolved order (overrides marked) and ask to proceed.
+# --yes skips the prompt but the order is still printed. --dry-run never reaches
+# here. Returns 0 to proceed, 1 to abort.
+confirm_order() {
+  local target_dir="$1"
+  echo "  build order (${VERSION_ID}):"
+  local d
+  for d in "${RESOLVED_ORDER[@]}"; do
+    local it=0; [[ "$d" == "$target_dir" ]] && it=1
+    local rdm=""; [[ "${HAS_README[$d]:-}" == 1 ]] && rdm="  [%README%]"
+    printf "    %-30s %s%s\n" "$(pkg_key "$d")" "$(cache_label "$d" "$it")" "$rdm"
+    echo "$(pkg_key "$d")" >> "$RUN_DIR/build-order.txt"
+  done
+  # note fetch deps (built via sbopkg in-container, not in the order list)
+  local fp
+  for fp in "${!FETCH_DEPS[@]}"; do
+    printf "    %-30s %s\n" "$fp" "fetch (sbopkg in container)"
+  done
+  [[ $ASSUME_YES -eq 1 ]] && return 0
+  local reply
+  read -rp "  Proceed? [Y/n] " reply
+  [[ -z "$reply" || "$reply" =~ ^[Yy]$ ]]
+}
+
+# run_target <target-slackbuild-dir>
+run_target() {
+  local target_dir="$1"
+  local tkey; tkey="$(pkg_key "$target_dir")"
+
+  echo
+  echo "=== Target: $tkey (${VERSION_ID}) ==="
+  resolve_target "$target_dir"
+  apply_overrides_to_order
+
+  # Hard resolution failures: report and stop, do not build.
+  if [[ ${#CYCLES[@]} -gt 0 || ${#UNMET[@]} -gt 0 ]]; then
+    local why=""
+    if [[ ${#UNMET[@]} -gt 0 ]]; then
+      local u
+      for u in "${!UNMET[@]}"; do why+="unmet:$u(${UNMET[$u]}) "; done
+    fi
+    [[ ${#CYCLES[@]} -gt 0 ]] && why+="${CYCLES[*]}"
+    ST_STATUS["$tkey"]="UNMET-DEP"
+    ST_REASON["$tkey"]="$why"
+    echo "  resolution failed: $why"
+    echo "  add an override rule ($TB_OVERRIDES) and rerun, or fix the tree." >&2
+    return
+  fi
+
+  if [[ $DRY_RUN -eq 1 ]]; then
+    echo "  build order (dry-run):"
+    local d
+    for d in "${RESOLVED_ORDER[@]}"; do
+      local it=0; [[ "$d" == "$target_dir" ]] && it=1
+      local rdm=""; [[ "${HAS_README[$d]:-}" == 1 ]] && rdm="  [%README%]"
+      printf "    %-30s %s%s\n" "$(pkg_key "$d")" "$(cache_label "$d" "$it")" "$rdm"
+      echo "$(pkg_key "$d")" >> "$RUN_DIR/build-order.txt"
+    done
+    local fp
+    for fp in "${!FETCH_DEPS[@]}"; do
+      printf "    %-30s %s\n" "$fp" "fetch (sbopkg in container)"
+    done
+    return
+  fi
+
+  if ! confirm_order "$target_dir"; then
+    echo "  aborted."
+    ST_STATUS["$tkey"]="ABORTED"
+    return
+  fi
+
+  # Per-run docker workdirs (host side, discarded after the run).
+  DEPS_DIR="$RUN_DIR/deps"; BUILD_OUT="$RUN_DIR/out"
+  mkdir -p "$DEPS_DIR" "$BUILD_OUT"
+
+  local d failed_progs=()
+  for d in "${RESOLVED_ORDER[@]}"; do
+    local key; key="$(pkg_key "$d")"
+    local prog; prog="$(basename "$d")"
+
+    if depends_on_failed "$d" failed_progs; then
+      ST_STATUS["$key"]="BLOCKED-BY-DEP"
+      ST_REASON["$key"]="blocked by failed dep"
+      [[ "${HAS_README[$d]:-}" == "1" ]] && ST_README["$key"]=1
+      echo "  $key: BLOCKED-BY-DEP"
+      failed_progs+=("$prog")
+      continue
+    fi
+
+    local it=0; [[ "$d" == "$target_dir" ]] && it=1
+    echo "  building $key ..."
+    if build_one "$d" "$it"; then
+      echo "  $key: ${ST_STATUS[$key]} (${ST_TIME[$key]}s)"
+    else
+      echo "  $key: ${ST_STATUS[$key]} (${ST_TIME[$key]}s)"
+      failed_progs+=("$prog")
+    fi
+  done
+}
+
+# =============================================================================
+# SUMMARY (ported)
+# =============================================================================
+print_summary() {
+  local total=$SECONDS
+  local succ=0 fail=0 blocked=0 cached=0
+  local summary="$RUN_DIR/summary.log"
+
+  {
+    echo "test-build run summary"
+    echo "target: $TARGET_ARG  version: $VERSION_ID"
+    echo
+  } > "$summary"
+
+  echo
+  echo "================ SUMMARY ================"
+  local key
+  for key in "${!ST_STATUS[@]}"; do
+    local st="${ST_STATUS[$key]}" rsn="${ST_REASON[$key]:-}" t="${ST_TIME[$key]:-0}"
+    local rd=""; [[ "${ST_README[$key]:-}" == "1" ]] && rd=" [%README%]"
+    local col="$C_YEL"
+    case "$st" in
+      SUCCESS) col="$C_GRN"; ((succ++)) ;;
+      CACHED)  col="$C_GRN"; ((cached++)) ;;
+      BLOCKED-BY-DEP|UNMET-DEP|ABORTED) col="$C_YEL"; ((blocked++)) ;;
+      *) col="$C_RED"; ((fail++)) ;;
+    esac
+    printf "%s%-30s %-16s%s %s%s (%ss)\n" "$col" "$key" "$st" "$C_RST" "$rsn" "$rd" "$t"
+    printf "%-30s %-16s %s%s (%ss)\n" "$key" "$st" "$rsn" "$rd" "$t" >> "$summary"
+  done
+  echo "----------------------------------------"
+  printf "%s%d succeeded%s, %s%d failed%s, %s%d blocked%s, %s%d cached%s, total %ss\n" \
+    "$C_GRN" "$succ" "$C_RST" "$C_RED" "$fail" "$C_RST" "$C_YEL" "$blocked" "$C_RST" \
+    "$C_GRN" "$cached" "$C_RST" "$total"
+  echo "logs: $RUN_DIR"
+  if [[ $fail -eq 0 && $blocked -eq 0 ]]; then
+    echo "${C_GRN}All green.${C_RST} Safe to build the SBo submission tarball on the host."
+  fi
+  {
+    echo
+    echo "$succ succeeded, $fail failed, $blocked blocked, $cached cached, total ${total}s"
+    echo "logs: $RUN_DIR"
+  } >> "$summary"
+}
+```
+
+Add the two workdir globals near the other globals (top of the flags block):
+
+```bash
+DEPS_DIR=""        # per-run host dir of built dep .txz, mounted into the container
+BUILD_OUT=""       # per-run host dir where built packages are copied out
+```
+
+- [ ] **Step 2: Sanity-check syntax**
+
+Run: `bash -n .extras/test-build`
+Expected: no output.
+
+- [ ] **Step 3: Self-check no regression**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add .extras/test-build
+SBOLINT=no git commit -m 'test-build: run_target orchestration + summary + confirm'
+```
+
+---
+
+## Task 9: Wire main(), image presence check, target lookup
+
+**Files:**
+- Modify: `.extras/test-build`
+
+- [ ] **Step 1: Implement the full main()**
+
+Replace the current `main()` in `.extras/test-build` with:
+
+```bash
+# Verify the selected image exists locally. It is built by a separate job; this
+# script only consumes it. (Later: a local-registry docker pull slots in here.)
+require_image() {
+  if ! docker image inspect "$ACTIVE_IMAGE" >/dev/null 2>&1; then
+    cat >&2 <<EOF
+Image not found locally: $ACTIVE_IMAGE
+It is produced by the separate image-builder job (full Slackware $VERSION_ID +
+sbo-maintainer-tools + sbopkg), stored on the NAS / local registry. Load or
+pull it, then rerun. This script does not build images.
+EOF
+    exit 1
+  fi
+}
+
+main() {
+  parse_args "$@"
+  init_color
+  require_config
+  SBO_TREE_ROOTS=("$ACTIVE_TREE")
+  load_overrides
+
+  # image + cache namespace (skip the image check on a pure dry-run so the order
+  # can be inspected without the image present).
+  if [[ $DRY_RUN -eq 0 ]]; then
+    command -v docker >/dev/null 2>&1 || { echo "docker not found in PATH." >&2; exit 1; }
+    require_image
+  fi
+  resolve_cache_root
+
+  RUN_DIR="$LOG_ROOT/$(date +%Y-%m-%d_%H-%M-%S)"
+  mkdir -p "$RUN_DIR"
+  : > "$RUN_DIR/build-order.txt"
+
+  # Single-package mode: resolve the name in the active tree.
+  local tdir
+  if ! tdir="$(find_slackbuild_dir "$TARGET_ARG")"; then
+    echo "Program not found in the SBo tree ($ACTIVE_TREE): $TARGET_ARG" >&2
+    exit 1
+  fi
+
+  run_target "$tdir"
+  print_summary
+}
+```
+
+- [ ] **Step 2: Sanity-check syntax**
+
+Run: `bash -n .extras/test-build`
+Expected: no output.
+
+- [ ] **Step 3: Dry-run smoke test against the real tree (no docker needed)**
+
+This needs a real config. If `~/.config/sbo-testbuild/config` is not set up,
+create a throwaway one pointing at an existing local SBo tree, then:
+
+Run: `.extras/test-build --dry-run <some-pkg-in-that-tree>`
+Expected: prints `=== Target: ... ===`, a build order, exits 0, no docker call.
+
+- [ ] **Step 4: Self-check no regression**
+
+Run: `bash .extras/test-logic.sh`
+Expected: PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add .extras/test-build
+SBOLINT=no git commit -m 'test-build: wire main, image-presence check, target lookup'
+```
+
+---
+
+## Task 10: Real end-to-end build (user-run) + README
+
+**Files:**
+- Modify: `.extras/test-build` (only if the real run surfaces a bug)
+- Create: `.extras/README.test-build` (short usage note)
+
+This task needs a real image and the buildsystem. Per repo rules the throwaway
+docker build is Claude-OK, but the IMAGE must exist first (separate job, not yet
+built). So this task is: document usage, and record the end-to-end run as a
+manual verification step the user performs once an image is available.
+
+- [ ] **Step 1: Write the usage README**
+
+Create `.extras/README.test-build`:
+
+```markdown
+# test-build
+
+Verify an already-published SBo package still builds on a target Slackware
+version inside a throwaway docker container.
+
+## Setup
+
+    mkdir -p ~/.config/sbo-testbuild
+    cp .extras/test-build-config.example ~/.config/sbo-testbuild/config
+    cp .extras/overrides.example        ~/.config/sbo-testbuild/overrides
+    $EDITOR ~/.config/sbo-testbuild/config
+
+Set the two SBo tree paths, the two image tags, LOG_ROOT, and PKG_CACHE.
+
+The images (`sbo-testbuild:current` / `:15.0`) are FULL Slackware installs plus
+`sbo-maintainer-tools` and `sbopkg`, built by a separate job (not this script).
+The script errors if the tagged image is not present locally.
+
+## Usage
+
+    .extras/test-build <pkg>            # build on -current (default)
+    .extras/test-build --stable <pkg>   # build on 15.0
+    .extras/test-build --dry-run <pkg>  # show the build order, no build
+    .extras/test-build --yes <pkg>      # skip the confirm (order still shown)
+    .extras/test-build --no-cache <pkg> # rebuild all deps this run
+
+A green run means it is safe to build the SBo submission tarball on the host.
+
+## current-vs-stable overrides
+
+`~/.config/sbo-testbuild/overrides` (see `overrides.example`) encodes deltas
+that only apply when building on -current:
+
+    drop:   <prog>            already in the -current base
+    rename: <old> -> <new>    renamed on -current
+    fetch:  <prog>            removed from the -current tree; built via sbopkg
+
+Start light; add rules only when a real package needs them.
+
+## Self-check
+
+    bash .extras/test-logic.sh
+```
+
+- [ ] **Step 2: Commit the docs**
+
+```bash
+git add .extras/README.test-build
+SBOLINT=no git commit -m 'test-build: usage README'
+```
+
+- [ ] **Step 3: Manual end-to-end verification (user, once an image exists)**
+
+Documented for the user to run when a `sbo-testbuild:*` image is available:
+
+```bash
+# pick a small already-published package with a dep, e.g. one already in the repo
+.extras/test-build --yes <pkg>
+```
+
+Expected: build order printed, deps built (or CACHED on a second run), target
+built, `sbopkglint` result shown, summary green, `All green.` line printed.
+A second run of the same package should show its deps as `CACHED`.
+
+Record the outcome. If a real bug surfaces (mount path, sbopkg invocation,
+package glob), fix it in `.extras/test-build` and re-run; add a self-check case
+if the bug was in pure logic.
+
+---
+
+## Self-Review
+
+Run this checklist against the spec after the plan is written:
+
+**1. Spec coverage:**
+- purpose / one-target-per-run: Task 2 (`parse_args`), Task 9 (`main`) - covered
+- two versions, current default: Task 2 (`--stable`, `select_version_paths`) - covered
+- resolve local tree + topo: Task 3 - covered
+- overrides drop/rename/fetch + UNMET stop: Task 4, stop in Task 8 `run_target` - covered
+- external config + overrides file: Task 2, Task 4 - covered
+- external image, presence check, no bake: Task 9 `require_image` - covered
+- container build (download/md5/build/installpkg): Task 7 - covered
+- fetch via sbopkg: Task 7 (`FETCH_LIST` loop) - covered
+- dep cache, digest-namespaced, --no-cache, target always fresh: Task 5, wired Task 7/8 - covered
+- target lint: Task 7 `lint_pkg`, called in Task 7 build_one - covered
+- confirm order + --yes still prints: Task 8 `confirm_order` - covered
+- --dry-run: Task 8 `run_target`, Task 9 skips image check - covered
+- report + logs (per-pkg, summary, build-order): Task 8 `print_summary`, Task 7 logs - covered
+- status values incl CACHED: Task 8 `print_summary` - covered
+- self-check parity: Tasks 1-6 - covered
+
+**2. Placeholder scan:** no TBD/TODO in code steps; every code step shows full
+code. The one deferred item (real end-to-end run) is explicit and gated on an
+external image, not a placeholder.
+
+**3. Type consistency:** function + global names match across tasks:
+`RESOLVED_ORDER`, `FETCH_DEPS`, `OV_DROP/OV_RENAME/OV_FETCH`, `CACHE_ROOT`,
+`ACTIVE_TREE/ACTIVE_IMAGE`, `DEPS_DIR/BUILD_OUT`, `cache_decision/cache_path/
+cache_store/cache_label`, `select_version_paths`, `apply_overrides_to_order`,
+`apply_rename`, `load_overrides`, `resolve_cache_root`, `require_image`,
+`build_one(dir,is_target)`, `run_target`, `confirm_order`, `print_summary`.
+Consistent.
+
+## Notes on deliberate simplifications
+
+- Single-package mode only (no category-folder / all / queue modes). This repo
+  bumps one package at a time. Extension point is `main`'s target lookup.
+- `-j` parallelism dropped entirely (was a no-op stub upstream). Builds serial.
+- fetch deps are not topo-ordered among themselves; sbopkg resolves their own
+  deps. Start light per the spec; revisit if a fetch dep needs another fetch dep.
+```
+