fix(installer): scope AUR list to filesystem, keep pacman.conf 0644HEADmain

The baked AUR set installed unconditionally, so zfs-auto-snapshot reached every target. On a btrfs install there's no zfs to satisfy its dependency, and pacstrap aborted the whole transaction. The ISO still bakes the full set. install_base now filters the manifest names through filter_aur_for_fs, dropping zfs-only tooling (zfs-auto-snapshot, zrepl) on a non-zfs target.

strip_repo_stanza mv'd a 0600 mktemp file onto the target, so a clean install shipped /etc/pacman.conf root-only and every user-level makepkg/yay failed to read it. It now truncate-writes through the existing file, preserving the pristine 0644.

Tested in test_common.bats.

3 files changed, 115 insertions, 1 deletions

diff --git a/installer/archangel b/installer/archangel
index f90b158..4805796 100755
--- a/installer/archangel
+++ b/installer/archangel
@@ -791,6 +791,11 @@ EOF
         info "Exposing baked AUR repo to pacstrap..."
         append_aur_repo /etc/pacman.conf "file://$aur_repo_dir"
         mapfile -t aur_packages < <(aur_manifest_names "$aur_repo_dir/manifest.tsv")
+        # Drop ZFS-only AUR tooling on a non-ZFS target. The baked repo carries
+        # the full set on every ISO, but e.g. zfs-auto-snapshot has a hard zfs
+        # dependency that can't resolve on a btrfs install and would abort the
+        # whole pacstrap transaction.
+        mapfile -t aur_packages < <(filter_aur_for_fs "$FILESYSTEM" "${aur_packages[@]}")
         info "Baked AUR packages to install: ${aur_packages[*]:-none}"
     fi
 
diff --git a/installer/lib/common.sh b/installer/lib/common.sh
index 0317034..0378756 100644
--- a/installer/lib/common.sh
+++ b/installer/lib/common.sh
@@ -166,6 +166,38 @@ aur_manifest_names() {
     awk -F'\t' 'NR>1 {print $1}' "$manifest"
 }
 
+# Print the baked AUR packages that are ZFS-only tooling, one per line. The ISO
+# bakes the full AUR set on every build, but these require a ZFS root:
+# zfs-auto-snapshot has a hard `zfs` dependency, and zrepl is ZFS replication.
+# On a non-ZFS install neither dependency exists, so installing them is at best
+# pointless and at worst aborts pacstrap (zfs-auto-snapshot's unmet `zfs` dep
+# fails the whole transaction). Keep in lockstep with build-aur.sh's
+# aur_v1_packages: a new ZFS-only AUR package added there belongs here too.
+aur_zfs_only_packages() {
+    printf '%s\n' \
+        zfs-auto-snapshot \
+        zrepl
+}
+
+# Filter a list of AUR package names for the target filesystem, printing the
+# kept names one per line in input order. On a ZFS target every package passes
+# through. On any other filesystem the ZFS-only tooling (aur_zfs_only_packages)
+# is dropped so it never reaches pacstrap. install_base runs the baked manifest
+# names through this before appending them to the pacstrap set.
+filter_aur_for_fs() {
+    local fs="$1"; shift
+    local -A drop=()
+    if [[ "$fs" != zfs ]]; then
+        local z
+        while IFS= read -r z; do drop["$z"]=1; done < <(aur_zfs_only_packages)
+    fi
+    local pkg
+    for pkg in "$@"; do
+        [[ -n "${drop[$pkg]:-}" ]] && continue
+        printf '%s\n' "$pkg"
+    done
+}
+
 # Remove the named repo's stanza (its [name] header and the config lines up to
 # the next [section] or EOF) from the pacman.conf at $2. Used to ensure the
 # installed target never references the baked [aur] repo, whose
@@ -181,7 +213,14 @@ strip_repo_stanza() {
         skip { next }
         { print }
     ' "$pacman_conf" > "$tmp"
-    mv "$tmp" "$pacman_conf"
+    # Truncate-write in place rather than `mv` the temp over the target: mktemp
+    # creates the temp 0600, and a mv would carry that onto pacman.conf,
+    # clobbering its pristine 0644 and leaving the installed config root-only.
+    # That broke every user-level makepkg/yay ("config file /etc/pacman.conf
+    # could not be read: Permission denied"). Writing through the existing file
+    # keeps its inode and mode.
+    cat "$tmp" > "$pacman_conf"
+    rm -f "$tmp"
 }
 
 #############################
diff --git a/tests/unit/test_common.bats b/tests/unit/test_common.bats
index 6f9d1b1..c76b6a4 100644
--- a/tests/unit/test_common.bats
+++ b/tests/unit/test_common.bats
@@ -666,6 +666,26 @@ Boot0001* ZFSBootMenu"
     rm -f "$f"
 }
 
+@test "strip_repo_stanza preserves the target file mode (no 0600 clobber)" {
+    local f
+    f=$(mktemp)
+    printf '%s\n' '[core]' '[aur]' 'Server = file:///usr/share/aur-packages' '[extra]' > "$f"
+    chmod 644 "$f"
+    strip_repo_stanza aur "$f"
+    [ "$(stat -c %a "$f")" = "644" ]
+    rm -f "$f"
+}
+
+@test "strip_repo_stanza preserves a non-default file mode" {
+    local f
+    f=$(mktemp)
+    printf '%s\n' '[core]' '[aur]' 'Server = x' '[extra]' > "$f"
+    chmod 640 "$f"
+    strip_repo_stanza aur "$f"
+    [ "$(stat -c %a "$f")" = "640" ]
+    rm -f "$f"
+}
+
 #############################
 # aur_repo_available
 #############################
@@ -720,3 +740,53 @@ Boot0001* ZFSBootMenu"
     [ "$status" -eq 0 ]
     [ -z "$output" ]
 }
+
+#############################
+# aur_zfs_only_packages / filter_aur_for_fs
+#############################
+
+@test "aur_zfs_only_packages lists zfs-auto-snapshot and zrepl" {
+    run aur_zfs_only_packages
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"zfs-auto-snapshot"* ]]
+    [[ "$output" == *"zrepl"* ]]
+}
+
+@test "filter_aur_for_fs zfs keeps every package including zfs-only tooling" {
+    run filter_aur_for_fs zfs downgrade yay zrepl zfs-auto-snapshot topgrade
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 5 ]
+    [[ "$output" == *"zfs-auto-snapshot"* ]]
+    [[ "$output" == *"zrepl"* ]]
+    [[ "$output" == *"yay"* ]]
+}
+
+@test "filter_aur_for_fs btrfs drops zfs-only tooling, keeps the rest" {
+    run filter_aur_for_fs btrfs downgrade yay zrepl zfs-auto-snapshot topgrade
+    [ "$status" -eq 0 ]
+    [ "${#lines[@]}" -eq 3 ]
+    [[ "$output" != *"zfs-auto-snapshot"* ]]
+    [[ "$output" != *"zrepl"* ]]
+    [[ "$output" == *"downgrade"* ]]
+    [[ "$output" == *"yay"* ]]
+    [[ "$output" == *"topgrade"* ]]
+}
+
+@test "filter_aur_for_fs btrfs with only zfs-only tooling prints nothing" {
+    run filter_aur_for_fs btrfs zfs-auto-snapshot zrepl
+    [ "$status" -eq 0 ]
+    [ -z "$output" ]
+}
+
+@test "filter_aur_for_fs with no package arguments prints nothing" {
+    run filter_aur_for_fs btrfs
+    [ "$status" -eq 0 ]
+    [ -z "$output" ]
+}
+
+@test "filter_aur_for_fs preserves input order" {
+    run filter_aur_for_fs zfs yay downgrade topgrade
+    [ "$status" -eq 0 ]
+    [ "${lines[0]}" = "yay" ]
+    [ "${lines[2]}" = "topgrade" ]
+}