chore(zcash): repin pczt stack to the upstream 2557 teststack

diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index a3e5329..20d3346 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -484,6 +484,7 @@ dependencies = [
  "hex",
  "incrementalmerkletree",
  "keystore",
+ "orchard",
  "pczt",
  "postcard",
  "rand_core 0.6.4",
@@ -1676,7 +1677,7 @@ checksum = "edd0f118536f44f5ccd48bcb8b111bdc3de888b58c74639dfb034a357d0f206d"
 [[package]]
 name = "equihash"
 version = "0.3.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "blake2b_simd",
  "corez",
@@ -1803,7 +1804,7 @@ dependencies = [
 [[package]]
 name = "f4jumble"
 version = "0.1.1"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "blake2b_simd",
 ]
@@ -3039,9 +3040,8 @@ checksum = "c08d65885ee38876c4f86fa503fb49d7b507c2b62552df7c70b2fce627e06381"
 
 [[package]]
 name = "orchard"
-version = "0.15.0-pre.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e8e277dd4b46f5d06deae3ffb8af1a951e8622368f028c2a4d6fe59339566403"
+version = "0.15.0-pre.2"
+source = "git+https://github.com/zcash/orchard?rev=475ef0ff77d45aebff93cb039d639250d82518a3#475ef0ff77d45aebff93cb039d639250d82518a3"
 dependencies = [
  "aes",
  "bitvec",
@@ -3142,7 +3142,7 @@ checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 [[package]]
 name = "pczt"
 version = "0.7.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "blake2b_simd",
  "bls12_381",
@@ -5409,13 +5409,13 @@ dependencies = [
 
 [[package]]
 name = "zcash_address"
-version = "0.12.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+version = "0.13.0-pre.0"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "bech32 0.11.0",
  "bs58",
  "corez",
- "f4jumble 0.1.1 (git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e)",
+ "f4jumble 0.1.1 (git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f)",
  "zcash_encoding",
  "zcash_protocol",
 ]
@@ -5423,7 +5423,7 @@ dependencies = [
 [[package]]
 name = "zcash_encoding"
 version = "0.4.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "corez",
  "hex",
@@ -5432,8 +5432,8 @@ dependencies = [
 
 [[package]]
 name = "zcash_keys"
-version = "0.14.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+version = "0.15.0-pre.0"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "bech32 0.11.0",
  "bip32",
@@ -5471,8 +5471,8 @@ dependencies = [
 
 [[package]]
 name = "zcash_primitives"
-version = "0.28.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+version = "0.29.0-pre.0"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "blake2b_simd",
  "block-buffer 0.11.0-rc.3",
@@ -5501,8 +5501,8 @@ dependencies = [
 
 [[package]]
 name = "zcash_protocol"
-version = "0.9.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+version = "0.10.0-pre.0"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "corez",
  "hex",
@@ -5540,8 +5540,8 @@ dependencies = [
 
 [[package]]
 name = "zcash_transparent"
-version = "0.8.0"
-source = "git+https://github.com/valargroup/librustzcash?rev=644b1ecf4679e17a9166782f57a795a4f4194d5e#644b1ecf4679e17a9166782f57a795a4f4194d5e"
+version = "0.9.0-pre.0"
+source = "git+https://github.com/valargroup/librustzcash?rev=94d6e7fd8c76abb1d909390e10254a22f587981f#94d6e7fd8c76abb1d909390e10254a22f587981f"
 dependencies = [
  "bip32",
  "bs58",
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index f351571..49763da 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -122,12 +122,16 @@ zeroize = { version = "1.8.2", default-features = false }
 # third party dependencies end
 
 [patch.crates-io]
-pczt = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
-zcash_address = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
-zcash_encoding = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
-zcash_keys = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
-zcash_primitives = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
-zcash_protocol = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
-zcash_transparent = { git = "https://github.com/valargroup/librustzcash", rev = "644b1ecf4679e17a9166782f57a795a4f4194d5e" }
+pczt = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+zcash_address = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+zcash_encoding = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+zcash_keys = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+zcash_primitives = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+zcash_protocol = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+zcash_transparent = { git = "https://github.com/valargroup/librustzcash", rev = "94d6e7fd8c76abb1d909390e10254a22f587981f" }
+# Redirect every crates.io `orchard` requirement onto the merged
+# unpadded-bundles head so the graph resolves to a single orchard node,
+# matching the pczt pin.
+orchard = { git = "https://github.com/zcash/orchard", rev = "475ef0ff77d45aebff93cb039d639250d82518a3" }
 # Use the upstream SDK rev with the Zcash batch registry types until they are published as a crate.
 ur-registry = { git = "https://github.com/KeystoneHQ/keystone-sdk-rust.git", rev = "0884de4b2e927bc3f95a98dff62045e0d492e574" }
diff --git a/rust/apps/zcash/Cargo.toml b/rust/apps/zcash/Cargo.toml
index 59ed83c..221e3f6 100644
--- a/rust/apps/zcash/Cargo.toml
+++ b/rust/apps/zcash/Cargo.toml
@@ -27,9 +27,13 @@ serde_with = { version = "3.11.0", features = [
 [dev-dependencies]
 keystore = { path = "../../keystore" }
 pczt = { version = "0.7", default-features = false, features = ["orchard", "sapling", "transparent", "zcp-builder"] }
-zcash_primitives = { version = "0.28", default-features = false, features = ["circuits", "test-dependencies", "transparent-inputs"] }
+zcash_primitives = { version = "0.29.0-pre.0", default-features = false, features = ["circuits", "test-dependencies", "transparent-inputs"] }
 incrementalmerkletree = { version = "0.8.2", default-features = false }
 shardtree = "0.6.2"
+# Nameable only so the transparent-only `legacy_test_support` can spell the
+# `BuildConfig::orchard_pool_bundle_type` value; orchard is already built transitively
+# via the `zcash_primitives` dev-dependency.
+orchard = { version = "0.15.0-pre.2", default-features = false }
 
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = [
diff --git a/rust/apps/zcash/src/errors.rs b/rust/apps/zcash/src/errors.rs
index cc24297..dc0e418 100644
--- a/rust/apps/zcash/src/errors.rs
+++ b/rust/apps/zcash/src/errors.rs
@@ -30,8 +30,8 @@ impl From<orchard::pczt::ParseError> for ZcashError {
 }
 
 #[cfg(feature = "cypherpunk")]
-impl From<zcash_vendor::pczt::orchard::BundleParseError> for ZcashError {
-    fn from(e: zcash_vendor::pczt::orchard::BundleParseError) -> Self {
+impl From<zcash_vendor::pczt::roles::low_level_signer::OrchardParseError> for ZcashError {
+    fn from(e: zcash_vendor::pczt::roles::low_level_signer::OrchardParseError) -> Self {
         Self::InvalidPczt(alloc::format!("Invalid Orchard bundle: {e:?}"))
     }
 }
diff --git a/rust/apps/zcash/src/lib.rs b/rust/apps/zcash/src/lib.rs
index a983518..38fdfd6 100644
--- a/rust/apps/zcash/src/lib.rs
+++ b/rust/apps/zcash/src/lib.rs
@@ -76,7 +76,8 @@ pub fn check_pczt_cypherpunk<P: consensus::Parameters>(
     // FUTURE(omitted-field-recompute): recompute-or-check omitted fields here,
     // mutating `pczt` so the normalized bytes carry the verified values forward.
     check_parsed_pczt_cypherpunk(params, &pczt, ufvk_text, seed_fingerprint, account_index)?;
-    Ok(pczt.serialize())
+    pczt.serialize()
+        .map_err(|e| ZcashError::InvalidPczt(alloc::format!("serialize normalized PCZT: {e:?}")))
 }
 
 /// `check_pczt_cypherpunk` against an already-parsed PCZT, so callers can parse
@@ -136,7 +137,8 @@ pub fn preflight_batch_pczt_cypherpunk<P: consensus::Parameters>(
     if actions.is_empty() {
         return Err(ZcashError::PcztNoMyInputs);
     }
-    Ok(pczt.serialize())
+    pczt.serialize()
+        .map_err(|e| ZcashError::InvalidPczt(alloc::format!("serialize normalized PCZT: {e:?}")))
 }
 
 /// Parses a multi-coins PCZT, checks policy, and serializes it again in one
@@ -157,7 +159,8 @@ pub fn check_pczt_multi_coins<P: consensus::Parameters>(
     // FUTURE(omitted-field-recompute): recompute-or-check omitted fields here,
     // mutating `pczt` so the normalized bytes carry the verified values forward.
     check_parsed_pczt_multi_coins(params, &pczt, xpub, seed_fingerprint, account_index)?;
-    Ok(pczt.serialize())
+    pczt.serialize()
+        .map_err(|e| ZcashError::InvalidPczt(alloc::format!("serialize normalized PCZT: {e:?}")))
 }
 
 /// `check_pczt_multi_coins` against an already-parsed PCZT, so callers can
@@ -385,19 +388,22 @@ mod legacy_tests {
     #[cfg(zcash_unstable = "nu6.3")]
     #[test]
     fn legacy_check_rejects_v6_pczt() {
-        let pczt = Creator::new_v6(
+        // `Creator::new(Nu6_3, ..)` alone yields a V6 PCZT (tx_version V6); the legacy
+        // path rejects it on version, so no Ironwood anchor is needed (and
+        // `with_ironwood_anchor` is orchard-feature-gated, unavailable in this build).
+        let pczt = Creator::new(
             BranchId::Nu6_3.into(),
             10,
             MainNetwork.coin_type(),
             [0; 32],
             [0; 32],
-            [1; 32],
         )
+        .unwrap()
         .build();
 
         let result = check_pczt_multi_coins(
             &MainNetwork,
-            &pczt.serialize(),
+            &pczt.serialize().unwrap(),
             "not-an-xpub",
             &[7u8; 32],
             0,
@@ -711,7 +717,9 @@ fn sign_checked_pczt_with_policy<P: consensus::Parameters>(
     } else {
         ensure_shielded_actions_are_signed(signed, &signable_actions)?
     };
-    Ok(signed.serialize())
+    signed
+        .serialize()
+        .map_err(|e| ZcashError::SigningError(alloc::format!("serialize signed PCZT: {e:?}")))
 }
 
 #[cfg(feature = "cypherpunk")]
@@ -727,14 +735,16 @@ mod tests {
     use super::*;
     extern crate std;
 
+    // Head of the v2 PCZT wire layout (`pczt::Pczt`'s v2 encoding), up to and including
+    // the Sapling bundle; empty bundles are omitted (`None`). The trailing Orchard and
+    // Ironwood bundles are captured as raw bytes via `postcard::take_from_bytes` and
+    // re-appended unchanged, so these fixtures only decode the fields at/before the one
+    // they mutate and never need the crate-private `orchard::v2::Bundle` layout.
     #[derive(Serialize, Deserialize)]
-    struct PcztMirror {
+    struct PcztHead {
         global: GlobalMirror,
-        transparent: ::pczt::transparent::Bundle,
-        sapling: SaplingBundleMirror,
-        orchard: ::pczt::orchard::Bundle,
-        #[cfg(zcash_unstable = "nu6.3")]
-        ironwood: ::pczt::orchard::Bundle,
+        transparent: Option<::pczt::transparent::Bundle>,
+        sapling: Option<SaplingBundleMirror>,
     }
 
     #[derive(Serialize, Deserialize)]
@@ -791,15 +801,21 @@ mod tests {
     #[cfg(zcash_unstable = "nu6.3")]
     fn v5_pczt_with_ironwood_actions() -> Vec<u8> {
         let sample = pczt::test_support::sample_ironwood_pczt();
-        let mut bytes = sample.bytes;
-        let mut pczt: PcztMirror = postcard::from_bytes(&bytes[8..]).unwrap();
-        assert!(!pczt.ironwood.actions().is_empty());
+        let bytes = sample.bytes;
+        assert!(!::pczt::Pczt::parse(&bytes)
+            .unwrap()
+            .ironwood()
+            .actions()
+            .is_empty());
+        let (mut head, rest) = postcard::take_from_bytes::<PcztHead>(&bytes[8..]).unwrap();
 
-        pczt.global.tx_version = constants::V5_TX_VERSION;
-        pczt.global.version_group_id = constants::V5_VERSION_GROUP_ID;
+        head.global.tx_version = constants::V5_TX_VERSION;
+        head.global.version_group_id = constants::V5_VERSION_GROUP_ID;
 
-        bytes.truncate(8);
-        postcard::to_extend(&pczt, bytes).unwrap()
+        let mut out = bytes[..8].to_vec();
+        out = postcard::to_extend(&head, out).unwrap();
+        out.extend_from_slice(rest);
+        out
     }
 
     fn assert_invalid_pczt_message<T: core::fmt::Debug>(result: Result<T>, expected: &str) {
@@ -813,23 +829,33 @@ mod tests {
         use ::pczt::roles::creator::Creator;
         use zcash_vendor::zcash_protocol::consensus::{BranchId, NetworkConstants};
 
-        let mut bytes = Creator::new(
+        let bytes = Creator::new(
             BranchId::Nu6.into(),
             10,
             MainNetwork.coin_type(),
             [0; 32],
             [0; 32],
         )
+        .unwrap()
         .build()
-        .serialize();
-        let mut pczt: PcztMirror = postcard::from_bytes(&bytes[8..]).unwrap();
-        assert!(pczt.sapling.spends.is_empty());
-        assert!(pczt.sapling.outputs.is_empty());
-
-        pczt.sapling.value_sum = 1;
+        .serialize()
+        .unwrap();
+        let (mut head, rest) = postcard::take_from_bytes::<PcztHead>(&bytes[8..]).unwrap();
+        // v2 omits empty bundles, so the freshly created PCZT has no Sapling bundle.
+        // Attach one that is empty except for a non-zero value sum, which `check` rejects.
+        assert!(head.sapling.is_none());
+        head.sapling = Some(SaplingBundleMirror {
+            spends: Vec::new(),
+            outputs: Vec::new(),
+            value_sum: 1,
+            anchor: [0u8; 32],
+            bsk: None,
+        });
 
-        bytes.truncate(8);
-        postcard::to_extend(&pczt, bytes).unwrap()
+        let mut out = bytes[..8].to_vec();
+        out = postcard::to_extend(&head, out).unwrap();
+        out.extend_from_slice(rest);
+        out
     }
 
     /// A PCZT whose Sapling bundle is empty but declares a non-zero value sum is malformed
@@ -912,6 +938,7 @@ mod tests {
                 sapling_anchor: None,
                 orchard_anchor: Some(orchard::Anchor::empty_tree()),
                 ironwood_anchor: None,
+                orchard_pool_bundle_type: orchard::builder::BundleType::DEFAULT,
             },
         );
         builder
@@ -943,7 +970,10 @@ mod tests {
         let PcztResult { pczt_parts, .. } = builder
             .build_for_pczt(OsRng, &zip317::FeeRule::standard())
             .unwrap();
-        let pczt_bytes = Creator::build_from_parts(pczt_parts).unwrap().serialize();
+        let pczt_bytes = Creator::build_from_parts(pczt_parts)
+            .unwrap()
+            .serialize()
+            .unwrap();
         let seed_fingerprint = calculate_seed_fingerprint(&victim_seed).unwrap();
 
         let expected =
@@ -1265,8 +1295,17 @@ mod tests {
     #[cfg(zcash_unstable = "nu6.3")]
     fn pczt_with_sapling_output() -> pczt::test_support::SamplePczt {
         let mut sample = pczt::test_support::sample_orchard_change_pczt();
-        let mut pczt: PcztMirror = postcard::from_bytes(&sample.bytes[8..]).unwrap();
-        pczt.sapling.outputs.push(SaplingOutputMirror {
+        let (mut head, rest) = postcard::take_from_bytes::<PcztHead>(&sample.bytes[8..]).unwrap();
+        // The orchard-change sample carries no Sapling bundle (v2 omits it); synthesize one
+        // with a single output and negative value sum so the batch check rejects it.
+        let mut sapling = head.sapling.take().unwrap_or(SaplingBundleMirror {
+            spends: Vec::new(),
+            outputs: Vec::new(),
+            value_sum: 0,
+            anchor: [0u8; 32],
+            bsk: None,
+        });
+        sapling.outputs.push(SaplingOutputMirror {
             cv: [0; 32],
             cmu: [0; 32],
             ephemeral_key: [0; 32],
@@ -1282,10 +1321,13 @@ mod tests {
             user_address: None,
             proprietary: BTreeMap::new(),
         });
-        pczt.sapling.value_sum = -1;
+        sapling.value_sum = -1;
+        head.sapling = Some(sapling);
 
-        sample.bytes.truncate(8);
-        sample.bytes = postcard::to_extend(&pczt, sample.bytes).unwrap();
+        let mut out = sample.bytes[..8].to_vec();
+        out = postcard::to_extend(&head, out).unwrap();
+        out.extend_from_slice(rest);
+        sample.bytes = out;
         sample
     }
 
diff --git a/rust/apps/zcash/src/pczt/mod.rs b/rust/apps/zcash/src/pczt/mod.rs
index 0587337..dcc39d8 100644
--- a/rust/apps/zcash/src/pczt/mod.rs
+++ b/rust/apps/zcash/src/pczt/mod.rs
@@ -295,6 +295,7 @@ pub(crate) mod test_support {
             .unwrap()
             .finish()
             .serialize()
+            .unwrap()
     }
 
     #[cfg(zcash_unstable = "nu6.3")]
@@ -331,6 +332,7 @@ pub(crate) mod test_support {
             .unwrap()
             .finish()
             .serialize()
+            .unwrap()
     }
 
     #[cfg(zcash_unstable = "nu6.3")]
@@ -391,6 +393,7 @@ pub(crate) mod test_support {
                 sapling_anchor: None,
                 orchard_anchor: None,
                 ironwood_anchor: Some(anchor),
+                orchard_pool_bundle_type: orchard::builder::BundleType::DEFAULT,
             },
         );
         builder
@@ -433,7 +436,7 @@ pub(crate) mod test_support {
             .finish();
 
         SamplePczt {
-            bytes: pczt.serialize(),
+            bytes: pczt.serialize().unwrap(),
             seed: seed.to_vec(),
             ufvk_text,
             seed_fingerprint,
@@ -503,6 +506,7 @@ pub(crate) mod test_support {
                 sapling_anchor: None,
                 orchard_anchor: Some(anchor),
                 ironwood_anchor: Some(orchard::Anchor::empty_tree()),
+                orchard_pool_bundle_type: orchard::builder::BundleType::DEFAULT,
             },
         );
         builder
@@ -545,7 +549,7 @@ pub(crate) mod test_support {
             .finish();
 
         SamplePczt {
-            bytes: pczt.serialize(),
+            bytes: pczt.serialize().unwrap(),
             seed: seed.to_vec(),
             ufvk_text,
             seed_fingerprint,
@@ -667,7 +671,7 @@ pub(crate) mod test_support {
             .finish();
 
         SamplePczt {
-            bytes: pczt.serialize(),
+            bytes: pczt.serialize().unwrap(),
             seed: seed.to_vec(),
             ufvk_text,
             seed_fingerprint,
@@ -743,6 +747,7 @@ pub(crate) mod legacy_test_support {
             .unwrap()
             .finish()
             .serialize()
+            .unwrap()
     }
 
     pub(crate) fn legacy_transparent_sample() -> LegacyTransparentSample {
@@ -780,6 +785,7 @@ pub(crate) mod legacy_test_support {
                 sapling_anchor: None,
                 orchard_anchor: None,
                 ironwood_anchor: None,
+                orchard_pool_bundle_type: orchard::builder::BundleType::DEFAULT,
             },
         );
         builder
@@ -822,7 +828,7 @@ pub(crate) mod legacy_test_support {
             .to_string();
 
         LegacyTransparentSample {
-            bytes: pczt.serialize(),
+            bytes: pczt.serialize().unwrap(),
             seed: seed.to_vec(),
             seed_fingerprint,
             xpub,
diff --git a/rust/apps/zcash/src/pczt/parse.rs b/rust/apps/zcash/src/pczt/parse.rs
index f0b6d81..e86b6af 100644
--- a/rust/apps/zcash/src/pczt/parse.rs
+++ b/rust/apps/zcash/src/pczt/parse.rs
@@ -813,14 +813,17 @@ mod legacy_tests {
     #[cfg(zcash_unstable = "nu6.3")]
     #[test]
     fn legacy_parse_rejects_v6_pczt() {
-        let pczt = Creator::new_v6(
+        // `Creator::new(Nu6_3, ..)` alone yields a V6 PCZT (tx_version V6); the legacy
+        // path rejects it on version, so no Ironwood anchor is needed (and
+        // `with_ironwood_anchor` is orchard-feature-gated, unavailable in this build).
+        let pczt = Creator::new(
             BranchId::Nu6_3.into(),
             10,
             MainNetwork.coin_type(),
             [0; 32],
             [0; 32],
-            [1; 32],
         )
+        .unwrap()
         .build();
 
         let result = parse_pczt_multi_coins(&MainNetwork, &[7u8; 32], &pczt);
diff --git a/rust/apps/zcash/src/pczt/sign.rs b/rust/apps/zcash/src/pczt/sign.rs
index bdaa8c1..3913733 100644
--- a/rust/apps/zcash/src/pczt/sign.rs
+++ b/rust/apps/zcash/src/pczt/sign.rs
@@ -83,7 +83,9 @@ pub fn sign_pczt(pczt: Pczt, seed: &[u8]) -> crate::Result<Vec<u8>> {
     let signer = pczt_ext::sign_transparent(signer, &SeedSigner { seed })
         .map_err(|e| ZcashError::SigningError(e.to_string()))?;
 
-    Ok(stamp_and_redact(signer.finish()).serialize())
+    stamp_and_redact(signer.finish())
+        .serialize()
+        .map_err(|e| ZcashError::SigningError(format!("serialize signed PCZT: {e:?}")))
 }
 
 #[cfg(not(feature = "cypherpunk"))]
@@ -243,7 +245,9 @@ impl PcztSigner for SeedSigner<'_> {
 /// Thin wrapper over `sign_pczt_to_pczt`; see it for the full contract.
 #[cfg(feature = "cypherpunk")]
 pub fn sign_pczt(pczt: Pczt, seed: &[u8]) -> crate::Result<Vec<u8>> {
-    Ok(sign_pczt_to_pczt(pczt, seed)?.serialize())
+    sign_pczt_to_pczt(pczt, seed)?
+        .serialize()
+        .map_err(|e| ZcashError::SigningError(format!("serialize signed PCZT: {e:?}")))
 }
 
 /// `sign_pczt`, but returns the stamped, redacted PCZT without serializing it,
@@ -427,6 +431,7 @@ mod tests {
     use super::*;
     // RoleSigner is the upstream reference signer; tests use its sighash as the
     // bit-exact oracle for the lean pczt_ext::shielded_sig_commitment.
+    use zcash_vendor::pczt::roles::redactor::Redactor;
     use zcash_vendor::pczt::roles::signer::Signer as RoleSigner;
 
     fn assert_invalid_pczt_message<T: core::fmt::Debug>(result: crate::Result<T>, expected: &str) {
@@ -542,19 +547,20 @@ mod tests {
         let base_sighash = RoleSigner::new(pczt.clone())
             .expect("Ironwood PCZT signer should initialize")
             .shielded_sighash();
-        let updated_anchor = orchard::Anchor::from_bytes([6u8; 32]).unwrap();
-        let updated_anchor_pczt = Updater::new(pczt.clone())
-            .set_v6_ironwood_anchor(updated_anchor)
-            .expect("v6 Ironwood anchor should be replaceable before proving")
+        // The v6 Ironwood sighash must not commit the anchor. The new stack has no
+        // post-parse anchor setter, so redact the anchor instead: parse substitutes a
+        // version-gated placeholder, and the shielded sighash must be unchanged.
+        let cleared_anchor_pczt = Redactor::new(pczt.clone())
+            .redact_ironwood_with(|mut r| r.clear_anchor())
             .finish();
         assert_ne!(
             pczt.ironwood().anchor(),
-            updated_anchor_pczt.ironwood().anchor()
+            cleared_anchor_pczt.ironwood().anchor()
         );
         assert_eq!(
             base_sighash,
-            RoleSigner::new(updated_anchor_pczt)
-                .expect("anchor-updated Ironwood PCZT signer should initialize")
+            RoleSigner::new(cleared_anchor_pczt)
+                .expect("anchor-cleared Ironwood PCZT signer should initialize")
                 .shielded_sighash(),
             "v6 Ironwood spend signatures must not commit to the anchor"
         );
@@ -748,14 +754,17 @@ mod legacy_tests {
     #[cfg(zcash_unstable = "nu6.3")]
     #[test]
     fn legacy_signing_rejects_v6_pczt() {
-        let pczt = Creator::new_v6(
+        // `Creator::new(Nu6_3, ..)` alone yields a V6 PCZT (tx_version V6); the legacy
+        // path rejects it on version, so no Ironwood anchor is needed (and
+        // `with_ironwood_anchor` is orchard-feature-gated, unavailable in this build).
+        let pczt = Creator::new(
             BranchId::Nu6_3.into(),
             10,
             MainNetwork.coin_type(),
             [0; 32],
             [0; 32],
-            [1; 32],
         )
+        .unwrap()
         .build();
 
         let result = sign_pczt(pczt, &[7u8; 32]);
diff --git a/rust/zcash_vendor/Cargo.toml b/rust/zcash_vendor/Cargo.toml
index 315ee8a..0dc6b3f 100644
--- a/rust/zcash_vendor/Cargo.toml
+++ b/rust/zcash_vendor/Cargo.toml
@@ -41,20 +41,20 @@ chacha20poly1305 = { version = "0.10.1", default-features = false, features = [
 ] }
 postcard = { version = "1.0.3", features = ["alloc"] }
 getset = { version = "0.1.3" }
-orchard = { version = "0.15.0-pre.1", default-features = false, optional = true }
+orchard = { version = "0.15.0-pre.2", default-features = false, optional = true }
 pczt = { version = "0.7", default-features = false }
 serde = { workspace = true }
 serde_with = { version = "3.11.0", features = [
     "alloc",
     "macros",
 ], default-features = false }
-transparent = { package = "zcash_transparent", version = "0.8", default-features = false, features = [
+transparent = { package = "zcash_transparent", version = "0.9.0-pre.0", default-features = false, features = [
     "transparent-inputs",
 ] }
-zcash_address = { version = "0.12", default-features = false }
+zcash_address = { version = "0.13.0-pre.0", default-features = false }
 zcash_encoding = { version = "0.4", default-features = false }
-zcash_keys = { version = "0.14", default-features = false }
-zcash_protocol = { version = "0.9", default-features = false }
+zcash_keys = { version = "0.15.0-pre.0", default-features = false }
+zcash_protocol = { version = "0.10.0-pre.0", default-features = false }
 zip32 = { version = "0.2", default-features = false }
 rust_tools = { workspace = true }
 #zcash end
@@ -65,7 +65,7 @@ unexpected_cfgs = { level = "warn", check-cfg = [
 ] }
 
 [dev-dependencies]
-transparent = { package = "zcash_transparent", version = "0.8", default-features = false, features = [
+transparent = { package = "zcash_transparent", version = "0.9.0-pre.0", default-features = false, features = [
     "transparent-inputs",
     "test-dependencies",
 ] }
diff --git a/rust/zcash_vendor/src/pczt_ext.rs b/rust/zcash_vendor/src/pczt_ext.rs
index 5fce6ae..301c97a 100644
--- a/rust/zcash_vendor/src/pczt_ext.rs
+++ b/rust/zcash_vendor/src/pczt_ext.rs
@@ -188,6 +188,31 @@ fn hash_transparent_tx_id(t_digests: Option<TransparentDigests>) -> Hash {
     h.finalize()
 }
 
+/// Orchard/Ironwood note ciphertext length; the ZIP-244 action digests slice it as
+/// 52 (compact) | 512 (memo) | 16 (non-compact).
+const ORCHARD_ENC_CIPHERTEXT_SIZE: usize = 580;
+
+/// The action's value-commitment bytes for the sighash. `cv_net` is `Option` in the v2
+/// PCZT wire model; the checked-PCZT preflight resolves it and `check::verify_cv_net`
+/// rejects any still-missing value before signing, so it is always present here. The zero
+/// fallback only keeps this infallible digest panic-free — a malformed PCZT then yields a
+/// non-matching sighash (an invalid signature), never a silent-but-valid one.
+fn action_cv_net(action: &pczt::orchard::Action) -> &[u8; 32] {
+    static ZERO: [u8; 32] = [0; 32];
+    action.cv_net().as_ref().unwrap_or(&ZERO)
+}
+
+/// The output's encrypted note ciphertext for the sighash. `resolve_fields` restores the
+/// full ciphertext from a memo-plaintext-only (`EncCiphertext::MemoPlaintext`) output; see
+/// [`action_cv_net`] for why the zero fallback is unreachable in the signing path.
+fn action_enc_ciphertext(output: &pczt::orchard::Output) -> &[u8] {
+    static ZERO: [u8; ORCHARD_ENC_CIPHERTEXT_SIZE] = [0; ORCHARD_ENC_CIPHERTEXT_SIZE];
+    match output.enc_ciphertext() {
+        pczt::orchard::EncCiphertext::Encrypted(c) if c.len() == ORCHARD_ENC_CIPHERTEXT_SIZE => c,
+        _ => &ZERO,
+    }
+}
+
 fn digest_orchard(pczt: &Pczt) -> Hash {
     let mut h = hasher(ZCASH_ORCHARD_HASH_PERSONALIZATION);
 
@@ -199,13 +224,13 @@ fn digest_orchard(pczt: &Pczt) -> Hash {
         ch.update(action.spend().nullifier());
         ch.update(action.output().cmx());
         ch.update(action.output().ephemeral_key());
-        ch.update(&action.output().enc_ciphertext()[..52]);
+        ch.update(&action_enc_ciphertext(action.output())[..52]);
 
-        mh.update(&action.output().enc_ciphertext()[52..564]);
+        mh.update(&action_enc_ciphertext(action.output())[52..564]);
 
-        nh.update(action.cv_net());
+        nh.update(action_cv_net(action));
         nh.update(action.spend().rk());
-        nh.update(&action.output().enc_ciphertext()[564..]);
+        nh.update(&action_enc_ciphertext(action.output())[564..]);
         nh.update(action.output().out_ciphertext());
     }
 
@@ -221,7 +246,9 @@ fn digest_orchard(pczt: &Pczt) -> Hash {
     };
     h.update(&value_balance.to_le_bytes());
 
-    h.update(pczt.orchard().anchor());
+    // v5 commits the anchor (v6 omits it). Present for well-formed v5 bundles; the empty
+    // fallback keeps this infallible — see `action_cv_net`.
+    h.update(pczt.orchard().anchor().as_ref().unwrap_or(&[0u8; 32]));
 
     h.finalize()
 }
@@ -354,13 +381,13 @@ fn digest_orchard_shaped_v6(
         ch.update(action.spend().nullifier());
         ch.update(action.output().cmx());
         ch.update(action.output().ephemeral_key());
-        ch.update(&action.output().enc_ciphertext()[..52]);
+        ch.update(&action_enc_ciphertext(action.output())[..52]);
 
-        mh.update(&action.output().enc_ciphertext()[52..564]);
+        mh.update(&action_enc_ciphertext(action.output())[52..564]);
 
-        nh.update(action.cv_net());
+        nh.update(action_cv_net(action));
         nh.update(action.spend().rk());
-        nh.update(&action.output().enc_ciphertext()[564..]);
+        nh.update(&action_enc_ciphertext(action.output())[564..]);
         nh.update(action.output().out_ciphertext());
     }
 
@@ -604,7 +631,7 @@ where
 pub fn sign_orchard<T>(llsigner: Signer, signer: &T) -> Result<Signer, T::Error>
 where
     T: PcztSigner,
-    T::Error: From<pczt::orchard::BundleParseError>,
+    T::Error: From<pczt::roles::low_level_signer::OrchardParseError>,
     T::Error: From<orchard::pczt::ParseError>,
     T::Error: From<transparent::pczt::ParseError>,
 {
@@ -657,7 +684,7 @@ where
 pub fn sign_ironwood<T>(llsigner: Signer, signer: &T) -> Result<Signer, T::Error>
 where
     T: PcztSigner,
-    T::Error: From<pczt::orchard::BundleParseError>,
+    T::Error: From<pczt::roles::low_level_signer::OrchardParseError>,
     T::Error: From<orchard::pczt::ParseError>,
     T::Error: From<transparent::pczt::ParseError>,
 {