diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 794b72fd7c663..200abe9ecdadf 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -2,7 +2,7 @@
 	"name": "Sapling",
 	"build": {
 		"context": "..",
-		"dockerfile": "../.github/workflows/sapling-cli-ubuntu-22.04.Dockerfile"
+		"dockerfile": "../.github/workflows/manylinux_2_34.Dockerfile"
 	},
 	"updateContentCommand": "ln -sf /workspaces/sapling/eden/scm/sl /usr/local/bin/sl",
 	"customizations": {
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a6a4c34c7e3e3..f1c1948e0fcb7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -99,7 +99,7 @@ else()
 endif()
 
 if(NOT CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD 17)
+  set(CMAKE_CXX_STANDARD 20)
   set(CMAKE_CXX_STANDARD_REQUIRED ON)
   message(STATUS "setting C++ standard to C++${CMAKE_CXX_STANDARD}")
 endif()
diff --git a/common/network/Hostname.h b/common/network/Hostname.h
new file mode 100644
index 0000000000000..d76ddbebff2cf
--- /dev/null
+++ b/common/network/Hostname.h
@@ -0,0 +1,40 @@
+/*
+ *  Copyright (c) 2004-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ *
+ */
+
+#pragma once
+
+namespace facebook {
+namespace network {
+
+constexpr std::string_view DOMAIN_SUFFIX = ".facebook.com";
+
+inline std::string getLocalHost(bool stripFbDomain) {
+    std::array<char, HOST_NAME_MAX + 1> buf{};
+
+    if (::gethostname(buf.data(), buf.size()) != 0) {
+        throw std::system_error(errno, std::generic_category(), "gethostname failed");
+    }
+
+    std::string hostname(buf.data());
+
+    if (stripFbDomain && 
+        hostname.size() >= DOMAIN_SUFFIX.size() &&
+        hostname.compare(hostname.size() - DOMAIN_SUFFIX.size(),
+                         DOMAIN_SUFFIX.size(),
+                         DOMAIN_SUFFIX) == 0)
+    {
+        hostname.resize(hostname.size() - DOMAIN_SUFFIX.size());
+    }
+
+    return hostname;
+}
+
+} // namespace network
+} // namespace facebook
diff --git a/eden/fs/CMakeLists.txt b/eden/fs/CMakeLists.txt
index 0065033347f82..0e0ffa2c40854 100644
--- a/eden/fs/CMakeLists.txt
+++ b/eden/fs/CMakeLists.txt
@@ -65,6 +65,7 @@ add_subdirectory(notifications)
 add_subdirectory(prjfs)
 add_subdirectory(py)
 add_subdirectory(rocksdb)
+add_subdirectory(rust/redirect_ffi)
 add_subdirectory(service)
 add_subdirectory(sqlite)
 add_subdirectory(store)
diff --git a/eden/fs/cli_rs/edenfs-client/BUCK b/eden/fs/cli_rs/edenfs-client/BUCK
index 6e3976bff4f10..83e6455bbb9ec 100644
--- a/eden/fs/cli_rs/edenfs-client/BUCK
+++ b/eden/fs/cli_rs/edenfs-client/BUCK
@@ -5,9 +5,6 @@ oncall("scm_client_infra")
 rust_library(
     name = "edenfs-client",
     srcs = glob(["src/**/*.rs"]),
-    named_deps = {
-        "hg_util": "//eden/scm/lib/util:util",
-    },
     os_deps = [
         (
             "windows",
diff --git a/eden/fs/cli_rs/edenfs-client/Cargo.toml b/eden/fs/cli_rs/edenfs-client/Cargo.toml
index eec86be9ada0d..6c51ae642f825 100644
--- a/eden/fs/cli_rs/edenfs-client/Cargo.toml
+++ b/eden/fs/cli_rs/edenfs-client/Cargo.toml
@@ -21,7 +21,6 @@ fbinit = { version = "0.2.0", git = "https://github.com/facebookexperimental/rus
 futures = { version = "0.3.31", features = ["async-await", "compat"] }
 futures_stats = { version = "0.1.0", git = "https://github.com/facebookexperimental/rust-shed.git", branch = "main" }
 hex = { version = "0.4.3", features = ["alloc"] }
-hg_util = { package = "sapling-util", version = "0.1.0", path = "../../../scm/lib/util" }
 lazy_static = "1.5"
 libc = "0.2.139"
 parking_lot = { version = "0.12.1", features = ["send_guard"] }
@@ -32,6 +31,7 @@ sapling-atomicfile = { version = "0.1.0", path = "../../../scm/lib/atomicfile" }
 sapling-config-remote-loader = { version = "0.1.0", path = "../../../scm/lib/config/remote-loader" }
 sapling-http-client = { version = "0.1.0", path = "../../../scm/lib/http-client" }
 sapling-thrift-types = { version = "0.1.0", path = "../../../scm/lib/thrift-types" }
+sapling-util = { version = "0.1.0", path = "../../../scm/lib/util" }
 serde = { version = "1.0.219", features = ["derive", "rc"] }
 serde_json = { version = "1.0.140", features = ["alloc", "float_roundtrip", "raw_value", "unbounded_depth"] }
 shlex = "1.3"
diff --git a/eden/fs/cli_rs/edenfs-client/src/instance.rs b/eden/fs/cli_rs/edenfs-client/src/instance.rs
index 81163b1a5f379..c4907376a04e4 100644
--- a/eden/fs/cli_rs/edenfs-client/src/instance.rs
+++ b/eden/fs/cli_rs/edenfs-client/src/instance.rs
@@ -106,9 +106,9 @@ use edenfs_utils::get_executable;
 #[cfg(windows)]
 use edenfs_utils::strip_unc_prefix;
 use fbinit::expect_init;
-use hg_util::lock::PathLock;
 use tracing::Level;
 use tracing::event;
+use util::lock::PathLock;
 
 use crate::client::EdenFsClient;
 use crate::use_case::UseCase;
diff --git a/eden/fs/cli_rs/edenfs-client/src/redirect.rs b/eden/fs/cli_rs/edenfs-client/src/redirect.rs
index 5ced316626e6c..1293c04f5827a 100644
--- a/eden/fs/cli_rs/edenfs-client/src/redirect.rs
+++ b/eden/fs/cli_rs/edenfs-client/src/redirect.rs
@@ -28,7 +28,6 @@ use edenfs_telemetry::EDEN_EVENTS_SCUBA;
 use edenfs_telemetry::send;
 use edenfs_utils::metadata::MetadataExt;
 use edenfs_utils::remove_symlink;
-use hg_util::path::absolute;
 #[cfg(target_os = "windows")]
 use mkscratch::zzencode;
 use pathdiff::diff_paths;
@@ -38,6 +37,7 @@ use serde::Deserialize;
 use serde::Deserializer;
 use serde::Serialize;
 use toml::value::Value;
+use util::path::absolute;
 
 use crate::checkout::CheckoutConfig;
 use crate::checkout::EdenFsCheckout;
diff --git a/eden/fs/cli_rs/edenfs-client/src/utils.rs b/eden/fs/cli_rs/edenfs-client/src/utils.rs
index a764794ed5e5c..0d14546ff39c6 100644
--- a/eden/fs/cli_rs/edenfs-client/src/utils.rs
+++ b/eden/fs/cli_rs/edenfs-client/src/utils.rs
@@ -13,7 +13,7 @@ use anyhow::Context;
 use anyhow::Result;
 use anyhow::anyhow;
 use anyhow::bail;
-use hg_util::path::expand_path;
+use util::path::expand_path;
 
 use crate::instance::DEFAULT_CONFIG_DIR;
 use crate::instance::DEFAULT_ETC_EDEN_DIR;
diff --git a/eden/fs/inodes/CMakeLists.txt b/eden/fs/inodes/CMakeLists.txt
index bb4e4cc22e7cb..9ed59fecfc39e 100644
--- a/eden/fs/inodes/CMakeLists.txt
+++ b/eden/fs/inodes/CMakeLists.txt
@@ -20,16 +20,17 @@ list(
   REMOVE_ITEM
   INODES_SRCS
   ${CMAKE_CURRENT_SOURCE_DIR}/RequestContext.cpp
-  ${CMAKE_CURRENT_SOURCE_DIR}/InodeNumber.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/InodeMetadata.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/InodeTimestamps.cpp
 )
 
 add_library(
   eden_inodes_inodenumber STATIC
-    ${CMAKE_CURRENT_SOURCE_DIR}/InodeNumber.cpp
+  InodeNumber.h
 )
 
+set_target_properties(eden_inodes_inodenumber PROPERTIES LINKER_LANGUAGE CXX)
+
 target_link_libraries(
   eden_inodes_inodenumber
   PUBLIC
@@ -79,6 +80,7 @@ else()
     PUBLIC
       eden_fuse
       eden_fscatalog
+      eden_fscatalog_dev
       eden_lmdb_catalog
       eden_overlay_checker
   )
@@ -116,6 +118,7 @@ target_link_libraries(
 
 add_subdirectory(overlay)
 add_subdirectory(fscatalog)
+add_subdirectory(fscatalog_dev)
 add_subdirectory(memcatalog)
 add_subdirectory(sqlitecatalog)
 add_subdirectory(lmdbcatalog)
diff --git a/eden/fs/inodes/fscatalog_dev/CMakeLists.txt b/eden/fs/inodes/fscatalog_dev/CMakeLists.txt
new file mode 100644
index 0000000000000..794dbbc5f29da
--- /dev/null
+++ b/eden/fs/inodes/fscatalog_dev/CMakeLists.txt
@@ -0,0 +1,23 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2.
+
+if (NOT WIN32)
+  file(GLOB OVERLAY_SRCS "*.cpp")
+  list(
+    REMOVE_ITEM OVERLAY_SRCS
+    "${CMAKE_CURRENT_SOURCE_DIR}/eden_fsck.cpp"
+  )
+  add_library(
+    eden_fscatalog_dev STATIC
+      ${OVERLAY_SRCS}
+  )
+  target_link_libraries(
+    eden_fscatalog_dev
+    PUBLIC
+      eden_overlay_thrift_cpp
+      eden_fuse
+      eden_utils
+  )
+endif()
diff --git a/eden/fs/inodes/sqlitecatalog/test/CMakeLists.txt b/eden/fs/inodes/sqlitecatalog/test/CMakeLists.txt
index 2a09466572954..1417c80432b4f 100644
--- a/eden/fs/inodes/sqlitecatalog/test/CMakeLists.txt
+++ b/eden/fs/inodes/sqlitecatalog/test/CMakeLists.txt
@@ -18,6 +18,7 @@ target_link_libraries(
     eden_model
     eden_sqlite
     eden_utils
+    edenfs_ffi
     Folly::folly
     ${LIBGMOCK_LIBRARIES}
 )
diff --git a/eden/fs/privhelper/CMakeLists.txt b/eden/fs/privhelper/CMakeLists.txt
index 7363021ff6649..da5e5dffbc290 100644
--- a/eden/fs/privhelper/CMakeLists.txt
+++ b/eden/fs/privhelper/CMakeLists.txt
@@ -3,7 +3,7 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2.
 
-file(GLOB PRIVHELPER_SRCS "*.cpp")
+file(GLOB PRIVHELPER_SRCS "*.cpp" "priority/*.cpp")
 
 add_library(
   eden_fuse_privhelper STATIC
diff --git a/eden/fs/rust/redirect_ffi/CMakeLists.txt b/eden/fs/rust/redirect_ffi/CMakeLists.txt
new file mode 100644
index 0000000000000..11a8d85ee1064
--- /dev/null
+++ b/eden/fs/rust/redirect_ffi/CMakeLists.txt
@@ -0,0 +1,57 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2.
+
+# Due to some tools changing '-' to '_' when building,
+# this library/crate is named using an '_' so that it can link successfully.
+rust_static_library(rust_redirect_ffi CRATE redirect_ffi USE_CXX_INCLUDE)
+
+install_rust_static_library(
+  rust_redirect_ffi
+  INSTALL_DIR lib
+)
+
+rust_cxx_bridge(
+  redirect_ffi
+  "src/lib.rs"
+  LIBS
+  fmt::fmt
+  Folly::folly
+)
+
+file(GLOB C_API_SRCS "src/*.cpp")
+file(GLOB C_API_HDRS "include/*.h")
+target_sources(
+  redirect_ffi
+  PRIVATE
+  "${C_API_SRCS}"
+)
+
+set_target_properties(
+  redirect_ffi
+  PROPERTIES
+  PUBLIC_HEADER
+  "${C_API_HDRS}"
+)
+
+target_include_directories(
+  redirect_ffi
+  PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>
+)
+target_link_libraries(
+  redirect_ffi
+  PUBLIC
+  rust_redirect_ffi
+  Folly::folly
+  edencommon::edencommon_utils
+  fmt::fmt
+)
+
+install(
+  TARGETS redirect_ffi
+  LIBRARY DESTINATION lib
+  PUBLIC_HEADER DESTINATION eden/scm/lib/redirect_ffi/include
+)
diff --git a/eden/fs/rust/redirect_ffi/Cargo.toml b/eden/fs/rust/redirect_ffi/Cargo.toml
index 58c2b291187e6..007fbc616304c 100644
--- a/eden/fs/rust/redirect_ffi/Cargo.toml
+++ b/eden/fs/rust/redirect_ffi/Cargo.toml
@@ -1,14 +1,21 @@
 # @generated by autocargo from //eden/fs/rust/redirect_ffi:redirect-ffi
 
 [package]
-name = "redirect-ffi"
+name = "redirect_ffi"
 version = "0.1.0"
 authors = ["Facebook Source Control Team <sourcecontrol-dev@fb.com>"]
 edition = "2024"
 license = "GPLv2+"
 
+[lib]
+name = "redirect_ffi"
+crate-type = ["lib", "staticlib"]
+
 [dependencies]
 anyhow = "1.0.98"
 cxx = "1.0.119"
 edenfs-client = { version = "0.1.0", path = "../../cli_rs/edenfs-client" }
 tokio = { version = "1.47.1", features = ["full", "test-util", "tracing"] }
+
+[build-dependencies]
+cxx-build = "1.0.119"
diff --git a/eden/fs/rust/redirect_ffi/build.rs b/eden/fs/rust/redirect_ffi/build.rs
deleted file mode 100644
index 2a623ae7d1ed6..0000000000000
--- a/eden/fs/rust/redirect_ffi/build.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This software may be used and distributed according to the terms of the
- * GNU General Public License version 2.
- */
-
-fn main() {
-    cxx_build::bridge("src/lib.rs");
-    println!("cargo:rerun-if-changed=src/lib.rs");
-}
diff --git a/eden/fs/service/CMakeLists.txt b/eden/fs/service/CMakeLists.txt
index 7f41ea2305370..8c97afda8c5a4 100644
--- a/eden/fs/service/CMakeLists.txt
+++ b/eden/fs/service/CMakeLists.txt
@@ -12,7 +12,7 @@ add_fbthrift_library(
     EdenService
   DEPENDS
     eden_config_thrift
-    fb303::fb303_thrift
+    fb303::fb303_core
 )
 add_fbthrift_library(
   streamingeden_thrift
@@ -33,13 +33,14 @@ file(GLOB SERVICE_SRCS "*.cpp")
 # eden/fs/thrift/ subdirectory, perhaps along with eden.thrift too.
 list(
   REMOVE_ITEM SERVICE_SRCS
-  ${CMAKE_CURRENT_SOURCE_DIR}/PrettyPrinters.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/PrivHelperMain.cpp
 )
+
 add_library(
   eden_service_thrift_util STATIC
-  PrettyPrinters.cpp
+  PrettyPrinters.h
 )
+set_target_properties(eden_service_thrift_util PROPERTIES LINKER_LANGUAGE CXX)
 target_link_libraries(
   eden_service_thrift_util
   PUBLIC
@@ -57,6 +58,11 @@ add_library(
   eden_service STATIC
   ${SERVICE_SRCS}
 )
+target_link_options(
+  eden_service
+  PUBLIC
+    -Wl,--allow-multiple-definition
+)
 target_link_libraries(
   eden_service
   PUBLIC
@@ -71,6 +77,7 @@ target_link_libraries(
     eden_store
     eden_takeover
     eden_telemetry
+    redirect_ffi
     ${EDEN_STORE_IMPLEMENTATIONS}
     ${YARPL_LIBRARIES}
     Folly::folly
diff --git a/eden/fs/service/EdenServer.cpp b/eden/fs/service/EdenServer.cpp
index b5443f87c8f00..45c1ccce9e657 100644
--- a/eden/fs/service/EdenServer.cpp
+++ b/eden/fs/service/EdenServer.cpp
@@ -50,6 +50,7 @@
 
 #include <csignal>
 
+#include "common/network/Hostname.h"
 #include "eden/common/telemetry/RequestMetricsScope.h"
 #include "eden/common/telemetry/SessionInfo.h"
 #include "eden/common/telemetry/StructuredLoggerFactory.h"
@@ -112,7 +113,6 @@
 
 #ifdef EDEN_HAVE_SERVER_OBSERVER
 #include "common/fb303/cpp/ThreadPoolExecutorCounters.h" // @manual
-#include "common/network/Hostname.h"
 #include "eden/fs/service/facebook/ServerObserver.h" // @manual
 #endif
 
diff --git a/eden/scm/lib/backingstore/CMakeLists.txt b/eden/scm/lib/backingstore/CMakeLists.txt
index 62bde26384d4a..e6751cbb7a18e 100644
--- a/eden/scm/lib/backingstore/CMakeLists.txt
+++ b/eden/scm/lib/backingstore/CMakeLists.txt
@@ -51,6 +51,7 @@ target_link_libraries(
   backingstore
   PUBLIC
   edencommon::edencommon_os
+  eden_config
   rust_backingstore
   fmt::fmt
   Folly::folly
diff --git a/eden/scm/lib/backingstore/Cargo.toml b/eden/scm/lib/backingstore/Cargo.toml
index 828459498893d..e162c8c07f2a4 100644
--- a/eden/scm/lib/backingstore/Cargo.toml
+++ b/eden/scm/lib/backingstore/Cargo.toml
@@ -1,7 +1,7 @@
 # @generated by autocargo from //eden/scm/lib/backingstore:backingstore
 
 [package]
-name = "sapling-backingstore"
+name = "backingstore"
 version = "0.1.0"
 authors = ["Meta Source Control Team <sourcecontrol-dev@meta.com>"]
 edition = "2024"
@@ -45,4 +45,6 @@ tracing-subscriber = { version = "0.3.20", features = ["chrono", "env-filter", "
 rand_chacha = "0.3"
 
 [features]
+cas = []
 fb = ["sapling-configloader/fb"]
+scuba = []
diff --git a/eden/scm/lib/backingstore/benches/Cargo.toml b/eden/scm/lib/backingstore/benches/Cargo.toml
index f956315e06d0b..327bb94a3e7b5 100644
--- a/eden/scm/lib/backingstore/benches/Cargo.toml
+++ b/eden/scm/lib/backingstore/benches/Cargo.toml
@@ -7,7 +7,7 @@ edition = "2024"
 
 [dependencies]
 fbinit = { version = "0.2.0", git = "https://github.com/facebookexperimental/rust-shed.git", branch = "main" }
-sapling-backingstore = { version = "0.1.0", path = ".." }
+backingstore = { version = "0.1.0", path = ".." }
 sapling-configloader = { version = "0.1.0", path = "../../config/loader" }
 sapling-identity = { version = "0.1.0", path = "../../identity" }
 sapling-minibench = { version = "0.1.0", path = "../../minibench" }
diff --git a/eden/scm/lib/edenfs_ffi/Cargo.toml b/eden/scm/lib/edenfs_ffi/Cargo.toml
index 2f1afd92c915a..f76f13adec0b6 100644
--- a/eden/scm/lib/edenfs_ffi/Cargo.toml
+++ b/eden/scm/lib/edenfs_ffi/Cargo.toml
@@ -1,7 +1,7 @@
 # @generated by autocargo from //eden/scm/lib/edenfs_ffi:edenfs_ffi
 
 [package]
-name = "sapling-edenfs_ffi"
+name = "edenfs_ffi"
 version = "0.1.0"
 authors = ["Meta Source Control Team <sourcecontrol-dev@meta.com>"]
 edition = "2024"