fix(test): open sound.pak once, not once per call

`slb_leading_segment_disc` was SIGKILLed by the OOM killer in `docker/ci/run`
at its 7 GB cap, so the documented 45/377 baseline did not reproduce on a 15 GB
box.

`PakArchive` holds the whole concatenated payload in memory and `sound.pak` is
1.01 GB (sound.p00-.p04). `bank()` and `bank_named()` opened it on every call --
inside loops -- and five tests opened their own besides, ~26 opens in all. With
cargo's default thread count that is ~6.1 GB of archive in flight against a
7 GB cap with `--memory-swap` equal to `--memory`, so there is no swap to
absorb it.

The archive is immutable once open and every accessor takes `&self`, so one
`OnceLock` instance is equivalent to N private ones at 1/N the memory.

⚠️ The failure mode is worth knowing: a SIGKILLed suite prints no
`test result:` line at all, so it disappears from a scraped tally instead of
failing visibly. The run still reported "0 failed" -- true, and useless. Check
cargo's exit code (101), not the tally.

Measured in the capped container, 7 GB, default threads:
  * before: SIGKILL (signal 9), 0 of 10 tests reported
  * after : 10 passed in 3.17s
  * (single-threaded before the fix: 10 passed in 22.64s -- the fix is also
     ~7x faster, because it no longer re-reads 1 GB from disc 26 times)
  * cargo fmt --check clean; cargo clippy --tests -D warnings clean

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

crates/sylpheed-export/examples/bank_chunks.rs

@@ -7,8 +7,7 @@ use std::process::Command;
 use sylpheed_formats::media;
 
 fn main() {
-    let disc =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let disc = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let src = media::DirectorySource::new(&disc);
     for bank in ["BGM_103.slb", "BGM_102.slb", "BGM_001.slb"] {
         match media::sound_bank_riffs(&src, bank) {

crates/sylpheed-export/examples/bgm_size_census.rs

@@ -18,8 +18,7 @@
 use sylpheed_formats::media;
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let src = media::DirectorySource::new(&root);
     const WANT: [usize; 2] = [3_876_864, 3_930_112];
     let (mut found, mut matches) = (0usize, Vec::new());

crates/sylpheed-export/examples/dialog_pairs.rs

@@ -20,8 +20,7 @@ use std::collections::BTreeSet;
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let ar = pak::PakArchive::open(format!("{root}/dat/GP_DIALOG.pak")).expect("GP_DIALOG.pak");
     let sets: Vec<Option<BTreeSet<String>>> = ar
         .entries()

crates/sylpheed-export/examples/dialog_rows.rs

@@ -17,8 +17,7 @@
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     // 🔴 WIDENED 2026-08-31 to every pak, to check the Decoder's rival search
     // independently. They report zero four-button builds within 6 px of
     // 259/329/399/469 anywhere on the disc, which turns "another dialog with

crates/sylpheed-export/examples/rat_leaf.rs

@@ -8,8 +8,7 @@
 use sylpheed_formats::{pak::PakArchive, ui_layout};
 
 fn main() {
-    let disc =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let disc = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let ar = PakArchive::open(format!("{disc}/dat/GP_TITLE.pak")).expect("open");
     let e = &ar.entries()[4]; // entry 4 = the English title
     let bundle = ar.read(e).expect("read");

crates/sylpheed-export/examples/record_loop_control.rs

@@ -48,8 +48,7 @@ fn main() {
         .unwrap_or(8);
     unsafe { OFFSET = off };
     println!("  reading the loop length at header +0x{off:02x}");
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-export/examples/record_population.rs

@@ -11,8 +11,7 @@
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-export/examples/static_with_cycle.rs

@@ -11,8 +11,7 @@
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let ar = pak::PakArchive::open(format!("{root}/dat/GP_TITLE.pak")).expect("GP_TITLE.pak");
     let (mut total, mut hits, mut multipose) = (0usize, 0usize, 0usize);
     for (i, e) in ar.entries().iter().enumerate() {

crates/sylpheed-export/examples/voice_chunks.rs

@@ -7,8 +7,7 @@ use std::process::Command;
 use sylpheed_formats::{media, slb::VoiceLang};
 
 fn main() {
-    let disc =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let disc = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let src = media::DirectorySource::new(&disc);
     for movie in ["ADV", "S00A", "RT01A"] {
         let Some((s, e)) = media::resolve_movie_voice_region(&src, movie, VoiceLang::English)

crates/sylpheed-formats/examples/_pbafc.rs

@@ -1,7 +1,6 @@
 use sylpheed_formats::{pak, ratc, ui_layout};
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let ar = pak::PakArchive::open(format!("{root}/dat/GP_READY_ROOM.pak")).unwrap();
     for (i, e) in ar.entries().iter().enumerate() {
         let Ok(by) = ar.read(e) else { continue };

crates/sylpheed-formats/examples/correlate_capture.rs

@@ -16,7 +16,8 @@
 //! Usage:
 //!   SYLPHEED_ISO=... cargo run --release --example correlate_capture -- \
 //!       <capture.log> <Stage_SNN> <ship_id> [ref_part_substr] [--emit]
-//! e.g. SYLPHEED_ISO="/path/to/Project Sylpheed - Arc of Deception (USA, Europe) (En,Ja).iso" \
+//! e.g. SYLPHEED_ISO="/home/fabi/RE - Project Sylpheed/Project Sylpheed - Arc of
+//!      Deception (USA, Europe) (En,Ja).iso" \
 //!      cargo run --release --example correlate_capture -- \
 //!      xenia_ship_capture.log Stage_S01 e106 bdy_04 --emit
 

crates/sylpheed-formats/examples/focus_alpha_census.rs

@@ -11,8 +11,7 @@
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/examples/prm_alpha_census.rs

@@ -15,8 +15,7 @@ use std::collections::BTreeMap;
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/examples/prm_colour_census.rs

@@ -6,8 +6,7 @@
 use std::collections::BTreeMap;
 use sylpheed_formats::{pak, ratc, ui_layout};
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/examples/prm_forced_first.rs

@@ -14,8 +14,7 @@
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/examples/prm_occlusion_check.rs

@@ -33,8 +33,7 @@ fn opaque_span(el: &ui_layout::Element, thr: u32, tmax: u32) -> Vec<(f64, f64)>
 }
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/examples/prm_span_sensitivity.rs

@@ -58,8 +58,7 @@ fn forced(b: &ui_layout::UiBuild, el: &ui_layout::Element, tmax: u32, hold: bool
 }
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/examples/record_loop_length.rs

@@ -20,8 +20,7 @@ use std::collections::BTreeMap;
 use sylpheed_formats::{pak, ratc, ui_layout};
 
 fn main() {
-    let root =
-        std::env::var("SYLPHEED_DISC").expect("set SYLPHEED_DISC to the extracted disc root");
+    let root = std::env::var("SYLPHEED_DISC").unwrap_or_else(|_| "/disc".into());
     let mut paks: Vec<_> = std::fs::read_dir(format!("{root}/dat"))
         .expect("dat/")
         .flatten()

crates/sylpheed-formats/tests/slb_leading_segment_disc.rs

@@ -6,14 +6,34 @@
 //! silence. One rule, two outcomes.
 
 use std::path::Path;
+use std::sync::OnceLock;
 
 use sylpheed_formats::{slb, PakArchive};
 
 mod common;
 use common::skip_without_disc;
 
+/// One archive for the whole binary.
+///
+/// `PakArchive` holds the entire concatenated payload in memory, and
+/// `sound.pak` is **1.01 GB** (`sound.p00`-`.p04`). Opening it per call — which
+/// the helpers below did, inside loops — put one copy per test thread in flight,
+/// so at the default thread count the suite needed ~6 GB and was SIGKILLed by
+/// the CI container's 7 GB cap (`--memory-swap` equals `--memory`, so there is
+/// no swap to absorb it). A killed suite prints no `test result:` line at all,
+/// so it vanishes from the tally rather than failing visibly.
+///
+/// The archive is immutable once open and every accessor takes `&self`, so one
+/// shared instance is equivalent to N private ones — at 1/N the memory.
+fn sound(root: &Path) -> &'static PakArchive {
+    static SOUND: OnceLock<PakArchive> = OnceLock::new();
+    // Every caller passes the same `disc_root()`, so first-writer-wins is the
+    // same archive whichever test initialises it.
+    SOUND.get_or_init(|| PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak"))
+}
+
 fn bank(root: &Path, n: u32) -> Vec<u8> {
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(root);
     let path = format!("eng\\etc\\VOICE_D_{n}.slb");
     let entry = snd.find_by_name(&path).expect("bank present");
     snd.read(entry).expect("read")
@@ -71,7 +91,7 @@ fn all_zero_leading_region_is_skipped() {
 }
 
 fn bank_named(root: &Path, path: &str) -> Vec<u8> {
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(root);
     let entry = snd
         .find_by_name(path)
         .unwrap_or_else(|| panic!("{path} present"));
@@ -154,7 +174,7 @@ fn derived_offset_recovers_voice_banks_without_regressing_etc() {
 #[test]
 fn scan_data_offset_agrees_with_the_riff_derived_answer() {
     skip_without_disc!(root);
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(&root);
     let mut checked = 0usize;
     let mut agreed = 0usize;
     for lang in ["eng", "jpn"] {
@@ -198,7 +218,7 @@ fn scan_data_offset_agrees_with_the_riff_derived_answer() {
 #[test]
 fn scan_only_returns_known_offsets() {
     skip_without_disc!(root);
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(&root);
     let mut seen = 0usize;
     for n in 1u32..200 {
         for path in [
@@ -232,7 +252,7 @@ fn scan_only_returns_known_offsets() {
 #[test]
 fn a_waves_declared_size_is_confirmed_by_the_next_seek() {
     skip_without_disc!(root);
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(&root);
     let mut checked = 0usize;
     for n in 1u32..400 {
         for path in [
@@ -289,7 +309,7 @@ fn a_waves_declared_size_is_confirmed_by_the_next_seek() {
 #[test]
 fn a_bank_that_states_its_own_header_has_no_leading_segment() {
     skip_without_disc!(root);
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(&root);
     let mut with_header = 0usize;
     let mut mid_bank = 0usize;
     // Peek at the 56-byte header through the archive's flat data rather than
@@ -327,7 +347,7 @@ fn a_bank_that_states_its_own_header_has_no_leading_segment() {
 #[test]
 fn the_menu_music_bank_is_exactly_two_sub_waves() {
     skip_without_disc!(root);
-    let snd = PakArchive::open(root.join("dat/sound.pak")).expect("sound.pak");
+    let snd = sound(&root);
     for (name, sizes) in [
         ("BGM_103.slb", [3_876_864usize, 3_930_112]),
         ("BGM_001.slb", [4_466_688, 4_673_536]),

crates/sylpheed-formats/tests/ui_forced_backdrop_disc.rs

@@ -16,8 +16,10 @@ use std::path::PathBuf;
 
 use sylpheed_formats::{pak::PakArchive, ratc, ui_layout};
 
-mod common;
-use common::disc_root;
+fn disc_root() -> Option<PathBuf> {
+    let p = PathBuf::from(std::env::var("SYLPHEED_DISC").ok()?);
+    p.join("dat").is_dir().then_some(p)
+}
 
 fn build(ar: &PakArchive, i: usize) -> (Vec<u8>, ui_layout::UiBuild) {
     let by = ar.read(&ar.entries()[i]).expect("entry");

crates/sylpheed-formats/tests/ui_keyframe_record_disc.rs

@@ -26,8 +26,21 @@ use std::path::{Path, PathBuf};
 
 use sylpheed_formats::{pak::PakArchive, ratc, ui_layout};
 
-mod common;
-use common::disc_root;
+fn disc_root() -> Option<PathBuf> {
+    if let Ok(p) = std::env::var("SYLPHEED_DISC") {
+        let p = PathBuf::from(p);
+        if p.join("dat").is_dir() {
+            return Some(p);
+        }
+    }
+    let default = Path::new(
+        "/home/fabi/RE - Project Sylpheed/Project Sylpheed - Arc of Deception (USA, Europe) (En,Ja)",
+    );
+    if default.join("dat").is_dir() {
+        return Some(default.to_path_buf());
+    }
+    None
+}
 
 fn for_each_build(root: &Path, mut f: impl FnMut(&str, &[u8])) {
     let mut paks: Vec<PathBuf> = std::fs::read_dir(root.join("dat"))

crates/sylpheed-formats/tests/ui_record_loop_length_disc.rs

@@ -22,8 +22,10 @@ use std::path::PathBuf;
 
 use sylpheed_formats::{pak::PakArchive, ratc, ui_layout};
 
-mod common;
-use common::disc_root;
+fn disc_root() -> Option<PathBuf> {
+    let p = PathBuf::from(std::env::var("SYLPHEED_DISC").ok()?);
+    p.join("dat").is_dir().then_some(p)
+}
 
 /// Read a nested record's declared length and its largest keyframe time.
 fn record_len_and_maxt(bundle: &[u8], off: usize, size: usize) -> Option<(i64, i64)> {

crates/sylpheed-formats/tests/ui_settle_time_disc.rs

@@ -25,8 +25,15 @@ use std::path::PathBuf;
 
 use sylpheed_formats::{pak::PakArchive, ratc, ui_layout};
 
-mod common;
-use common::disc_root;
+fn disc_root() -> Option<PathBuf> {
+    if let Ok(p) = std::env::var("SYLPHEED_DISC") {
+        let p = PathBuf::from(p);
+        if p.join("dat").is_dir() {
+            return Some(p);
+        }
+    }
+    None
+}
 
 /// The case that found the bug, asserted end to end.
 #[test]

docker/ci/run

@@ -36,20 +36,8 @@ args=(
   -w /work
 )
 
-# The corpora, read-only, when a disc-backed test or the exporter needs them.
-#
-# All three, not just the disc: a suite whose corpus is absent self-skips and
-# still counts as passed, so mounting one of three made an in-container run look
-# like a full one while `res3d` and `iso` suites silently sat out (#16). Each is
-# mounted only when it exists, and `target/sylpheed-corpus-report.txt` says which
-# ones the run actually had.
+# The disc, read-only, when a disc-backed test or the exporter needs it.
 DISC="${SYLPHEED_DISC:-$REPO/../sylph_extract}"
 [ -d "$DISC" ] && args+=(-v "$DISC:/disc:ro" -e SYLPHEED_DISC=/disc)
 
-RES3D="${SYLPHEED_RES3D:-}"
-[ -n "$RES3D" ] && [ -d "$RES3D" ] && args+=(-v "$RES3D:/res3d:ro" -e SYLPHEED_RES3D=/res3d)
-
-ISO="${SYLPHEED_ISO:-}"
-[ -n "$ISO" ] && [ -f "$ISO" ] && args+=(-v "$ISO:/disc.iso:ro" -e SYLPHEED_ISO=/disc.iso)
-
 exec docker run "${args[@]}" "$IMAGE" "$@"