build: relink only static initfs binaries on boot-ABI change, not the desktop

The ABI-staleness step recompiled the ENTIRE dynamically-linked userspace (Qt,
KF6, mesa, sddm) whenever relibc/base/a-protocol-fork changed -- so editing a
driver, acpi, or base recipe rebuilt the whole desktop. That is wrong: relibc is
a shared libc.so.6, resolved at runtime (upgrading glibc on Linux does not
recompile the system); `base` ships no libraries. Only the STATIC boot-critical
initfs binaries (getty/redoxfs/init/randd -> base/redoxfs/userutils/bootstrap)
bake in the scheme/syscall protocol and can go stale. Invalidate only those.
Removes: the relibc|base blanket USERSPACE trigger, the wipe-every-build/sysroot
step, and the repo-wide pkgar sweep. Genuine relibc C-ABI break -> --no-cache.

local/scripts/build-redbear.sh

@@ -628,7 +628,9 @@ if [ "$NO_CACHE" != "1" ]; then
                 find "$PROJECT_ROOT/recipes" -path "*/$src/target" -type d -exec rm -rf {} + 2>/dev/null || true
                 STALE_DETECTED=1
                 [ "$src" = "relibc" ] && RELIBC_INVALIDATED=1
-                case "$src" in relibc|base) USERSPACE_RUNTIME_STALE=1 ;; esac
+                # NB: base ships NO libraries (daemons/drivers/init) and relibc is
+                # a shared libc.so.6 — neither forces a userspace-wide relink. Only
+                # the static initfs-critical binaries are handled, selectively, below.
             fi
         fi
     done
@@ -661,13 +663,11 @@ if [ "$NO_CACHE" != "1" ]; then
     done
 
 
-    if [ "$USERSPACE_RUNTIME_STALE" = "1" ] && [ "${REDBEAR_SKIP_ABI_STALENESS:-0}" != "1" ]; then
-        echo ">>> Cleaning stale build/sysroot dirs (userspace-linked runtime changed)..."
-        find "$PROJECT_ROOT/recipes" "$PROJECT_ROOT/local/recipes" \
-            \( -path "*/target/x86_64-unknown-redox/build" \
-            -o -path "*/target/x86_64-unknown-redox/sysroot" \) \
-            -type d -exec rm -rf {} + 2>/dev/null || true
-    fi
+    # (The blanket "wipe every recipe's build/sysroot when a runtime fork changed"
+    # step used to live here. It was the bug: it recompiled the entire dynamically
+    # -linked desktop — Qt, KF6, mesa, sddm — on any relibc/base/syscall change,
+    # which is exactly what a shared-libc system never needs. Replaced by the
+    # selective, static-consumer-only invalidation below.)
 
     # Downstream ABI-staleness prevention (relibc consumers).
     #
@@ -739,78 +739,36 @@ if [ "$NO_CACHE" != "1" ]; then
             *) return 1 ;;
         esac
     }
-    # ── Config-scoped ABI invalidation ──────────────────────────────────
-    # repo/ is shared across configs, so a `redbear-mini` build must NOT nuke
-    # packages that only `redbear-full` builds (Qt, mesa, sddm, ...) just because
-    # their pkgars sit in the repo older than relibc.pkgar. Resolve the closure
-    # of the config being built and only ever invalidate packages inside it.
-    # No env flag needed — you named the config, so we know it's mini not full.
-    declare -A _config_pkg_set
-    _config_scoped=0
-    _cfg_file="$PROJECT_ROOT/config/$CONFIG.toml"
-    if [ -f "$_cfg_file" ]; then
-        while read -r _p; do
-            [ -n "$_p" ] && _config_pkg_set["$_p"]=1
-        done < <(timeout 120 "$PROJECT_ROOT/target/release/repo" push-tree \
-                     --filesystem="$_cfg_file" 2>/dev/null \
-                   | sed -E 's/^[^A-Za-z0-9_]+//' | awk '{print $1}' | grep -E '^[A-Za-z0-9]')
-        [ "${#_config_pkg_set[@]}" -gt 0 ] && _config_scoped=1
-    fi
-    if [ "$_config_scoped" = "1" ]; then
-        echo ">>> ABI-staleness scoped to $CONFIG (${#_config_pkg_set[@]} pkgs); other configs' repo packages untouched."
-    else
-        echo ">>> NOTE: could not resolve $CONFIG package closure; ABI sweep is repo-wide (fallback)."
-    fi
-    _pkg_in_config() {
-        # true unless we have a config closure and pkg is outside it
-        [ "$_config_scoped" != "1" ] && return 0
-        [ -n "${_config_pkg_set[$1]:-}" ]
-    }
-    invalidate_consumer() {
-        local pkg="$1"
-        _pkg_in_config "$pkg" || return 0
-        rm -f "$REPO_DIR/$pkg".*
-        find "$PROJECT_ROOT/recipes" "$PROJECT_ROOT/local/recipes" \
-            -path "*/$pkg/target" -type d -exec rm -rf {} + 2>/dev/null || true
-    }
-    if [ "${REDBEAR_SKIP_ABI_STALENESS:-0}" = "1" ]; then
-        # Fast-iteration escape hatch: skip the entire relibc-consumer
-        # invalidation. Safe ONLY when relibc's ABI is unchanged (e.g. iterating
-        # on a single driver/app recipe). The cookbook's own BLAKE3 dep-hash
-        # cache still rebuilds recipes whose sources changed, so your edited
-        # package re-cooks while everything else stays cached — no 30-min churn
-        # to re-reach it. Unset to restore the stale-binary safety net (which is
-        # required whenever relibc/base actually changed).
-        echo ">>> REDBEAR_SKIP_ABI_STALENESS=1 — skipping relibc-consumer invalidation"
-        echo ">>> (fast iteration; assumes relibc ABI unchanged). Unset to restore it."
-    elif [ "$relibc_rebuilding" = "1" ]; then
-        echo ">>> relibc is rebuilding — it is statically linked into every"
-        echo ">>> userspace binary, so ALL packages are invalidated to force a"
-        echo ">>> clean relink (correctness over speed; prevents stale-binary skew)."
-        for _pkgar in "$REPO_DIR"/*.pkgar; do
-            [ -f "$_pkgar" ] || continue
-            _pkg="$(basename "$_pkgar" .pkgar)"
-            _pkg_in_config "$_pkg" || continue
-            if _rb_preserve_toolchain "$_pkg"; then
-                echo ">>> preserving ABI-inert toolchain pkg '$_pkg' (consumer relinks;" \
-                     "set REDBEAR_FORCE_TOOLCHAIN_RECOOK=1 to force a full re-cook)."
-                continue
-            fi
-            invalidate_consumer "$_pkg"
-        done
-    elif [ -f "$RELIBC_PKGAR" ]; then
-        relibc_ts=$(stat -c %Y "$RELIBC_PKGAR" 2>/dev/null || echo "0")
-        for _pkgar in "$REPO_DIR"/*.pkgar; do
-            [ -f "$_pkgar" ] || continue
-            _pkg="$(basename "$_pkgar" .pkgar)"
-            [ "$_pkg" = "relibc" ] && continue
-            _pkg_in_config "$_pkg" || continue
-            _rb_preserve_toolchain "$_pkg" && continue
-            _pkg_ts=$(stat -c %Y "$_pkgar" 2>/dev/null || echo "0")
-            if [ "$relibc_ts" != "0" ] && [ "$relibc_ts" -gt "$_pkg_ts" ]; then
-                echo ">>> ABI-stale $_pkg (older than relibc.pkgar — interrupted prior build); invalidating..."
-                invalidate_consumer "$_pkg"
-            fi
+    # ── Selective, static-consumer-only ABI invalidation ───────────────
+    # relibc is a SHARED library (libc.so.6): dynamically-linked userspace — Qt,
+    # KF6, mesa, sddm, the whole desktop — resolves it at RUNTIME, so a relibc
+    # rebuild needs NO recompile there. That is exactly why upgrading glibc on
+    # Linux does not recompile the system. `base` ships no libraries at all
+    # (daemons/drivers/init). The ONLY binaries that can genuinely go stale are
+    # the STATIC, boot-critical initfs binaries that bake in the Redox
+    # scheme/syscall protocol before libc.so is available — the getty / redoxfs /
+    # init / randd class. Those come from a small fixed set of forks; when the
+    # boot ABI changes (relibc rebuilds, or a syscall/libredox/redox-scheme
+    # protocol crate changed -> USERSPACE_RUNTIME_STALE), relink ONLY them.
+    #
+    # This restores the selective rule the old "nuke every pkgar + wipe every
+    # build/sysroot" version had replaced (which recompiled the entire desktop on
+    # any driver/acpi/base edit). For a genuine relibc *C-ABI* break — a libc
+    # struct/inline baked into a compiled consumer, which is rare — force a full
+    # clean rebuild with `--no-cache`.
+    ABI_CRITICAL_PKGS="base redoxfs userutils bootstrap"
+    _boot_abi_changed=0
+    [ "$relibc_rebuilding" = "1" ] && _boot_abi_changed=1
+    [ "$USERSPACE_RUNTIME_STALE" = "1" ] && _boot_abi_changed=1
+    if [ "$_boot_abi_changed" = "1" ]; then
+        echo ">>> Boot ABI touched (relibc / syscall protocol fork) — relinking ONLY the"
+        echo ">>> static initfs-critical binaries: $ABI_CRITICAL_PKGS."
+        echo ">>> Dynamically-linked userspace (Qt/KF6/mesa/sddm/desktop) is untouched —"
+        echo ">>> shared libc.so resolved at runtime (the Linux glibc model)."
+        for _pkg in $ABI_CRITICAL_PKGS; do
+            rm -f "$REPO_DIR/$_pkg".*
+            find "$PROJECT_ROOT/recipes" "$PROJECT_ROOT/local/recipes" \
+                -path "*/$_pkg/target" -type d -exec rm -rf {} + 2>/dev/null || true
         done
     fi
 fi