diff --git a/README.md b/README.md
index 104b2481..01214a49 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ C library.
 
 ```toml
 [dependencies]
-openkal-llvm-runtime = "0.19.1"
+openkal-llvm-runtime = "0.19.2"
 ```
 
 > **Engine floor (mcpp 2026.11.2.1):** 0.17.0 is built over openkal-musl 0.26.0,
@@ -330,6 +330,18 @@ grants against raw file truncation. The runtime implementation is unchanged.
 
 ## OpenKal 0.24 dependency group
 
+Runtime 0.19.2 keeps the volume where a name is rebuilt part by part. `X:` is a
+root name only with the separator after it, so `lexically_normal` appended `D:` as
+an ordinary name and the root directory replaced it (`D:/a/./b` became `/a/b`), and
+so did `weakly_canonical`, which ends in it, and `path("D:/a") / "/b"`. On Windows a
+program over the hosted arrangement then named every file beneath no volume: a
+launcher could not start its runner (mcpp-community/mcpp#889). `lexically_normal`
+now begins its result with the volume and its root directory as written, and
+appending a rooted name beneath a volume keeps the volume (`D:/b`), as
+[fs.path.append] states it for a system with root names. Both probes state the
+three results; without the change two fail on Linux and under the Windows hosted
+arrangement.
+
 Runtime 0.19.1 reads a name beneath a volume, `X:/...`, as the C library beneath
 does: `X:` is the root name and `/` the root directory, so the working directory on
 a system with volumes is absolute and `absolute`, `canonical` and `relative` keep
diff --git a/examples/cxx/src/main.cpp b/examples/cxx/src/main.cpp
index c95e13c5..8c113fb2 100644
--- a/examples/cxx/src/main.cpp
+++ b/examples/cxx/src/main.cpp
@@ -153,6 +153,15 @@ int main() {
         check(fs::absolute(cwd, cwd_ec) == cwd && !cwd_ec, "absolute() of it is itself");
         const fs::path can = fs::canonical(cwd, cwd_ec);
         check(!cwd_ec && can.is_absolute(), "canonical() of it succeeds");
+        // 0.19.2: a builder that appends element by element keeps the volume.
+        check((fs::path("D:/a") / "/b") == "D:/b" && (fs::path("D:/a") / fs::path("/b")) == "D:/b"
+                  && fs::path("D:/a").append(std::string("/b")) == "D:/b", "a rooted name appended beneath a volume keeps it");
+        check(fs::path("D:/a/./b/../c").lexically_normal() == "D:/a/c" && fs::path("D:/").lexically_normal() == "D:/",
+              "lexically_normal() keeps the volume");
+        check((fs::path("/a") / "/b") == "/b" && fs::path("/a/../b").lexically_normal() == "/b", "and `/' is unchanged");
+        const fs::path missing = cwd / "openkal-no-such-name" / "." / "x";
+        const fs::path weak = fs::weakly_canonical(missing, cwd_ec);
+        check(!cwd_ec && weak.is_absolute() && weak.root_name() == cwd.root_name(), "weakly_canonical() keeps the working directory's volume");
     }
 
     // --- std::filesystem, which is the C++ face of openkal.fs ---------------
diff --git a/examples/image-cxx/src/main.cpp b/examples/image-cxx/src/main.cpp
index 3250b646..21b91bd7 100644
--- a/examples/image-cxx/src/main.cpp
+++ b/examples/image-cxx/src/main.cpp
@@ -63,6 +63,15 @@ int main(int argc, char** argv) {
         check(fs::absolute(cwd, cwd_ec) == cwd && !cwd_ec, "absolute() of it is itself");
         const fs::path can = fs::canonical(cwd, cwd_ec);
         check(!cwd_ec && can.is_absolute(), "canonical() of it succeeds");
+        // 0.19.2: a builder that appends element by element keeps the volume.
+        check((fs::path("D:/a") / "/b") == "D:/b" && (fs::path("D:/a") / fs::path("/b")) == "D:/b"
+                  && fs::path("D:/a").append(std::string("/b")) == "D:/b", "a rooted name appended beneath a volume keeps it");
+        check(fs::path("D:/a/./b/../c").lexically_normal() == "D:/a/c" && fs::path("D:/").lexically_normal() == "D:/",
+              "lexically_normal() keeps the volume");
+        check((fs::path("/a") / "/b") == "/b" && fs::path("/a/../b").lexically_normal() == "/b", "and `/' is unchanged");
+        const fs::path missing = cwd / "openkal-no-such-name" / "." / "x";
+        const fs::path weak = fs::weakly_canonical(missing, cwd_ec);
+        check(!cwd_ec && weak.is_absolute() && weak.root_name() == cwd.root_name(), "weakly_canonical() keeps the working directory's volume");
     }
 
     std::println("-- failures: {} --", failures);
diff --git a/llvm/PATCHES.md b/llvm/PATCHES.md
index 37a3a31a..b64b81eb 100644
--- a/llvm/PATCHES.md
+++ b/llvm/PATCHES.md
@@ -29,10 +29,10 @@ grep -rn "openkal ─── BEGIN" llvm/
 
 ## 已替换
 
- 六处,五个文件,一个判据 —— 每一处都能填进上面那句话。
+ 七处,六个文件,一个判据 —— 每一处都能填进上面那句话。
 
 ```sh
-grep -rn "openkal ─── BEGIN" llvm/    # 30 处 BEGIN 标记
+grep -rn "openkal ─── BEGIN" llvm/    # 31 处 BEGIN 标记
 ```
 
 | 文件 | 上游按什么分派 | 平台面 | openkal 的答案 |
@@ -43,6 +43,7 @@ grep -rn "openkal ─── BEGIN" llvm/    # 30 处 BEGIN 标记
 | `libunwind/src/UnwindCursor.hpp` | `_WIN32` | (无) | 整段没被用到,只是被 include |
 | `compiler-rt/…/emutls.c` | `_WIN32` | 互斥 + 对齐分配 | pthread + `posix_memalign` |
 | `libcxx/src/filesystem/path_parser.h` | `_LIBCPP_WIN32API` | 名字的根 | C 库的根：`/` 与 `X:/`（0.19.1） |
+| `libcxx/src/filesystem/path.cpp` | （无，`/=` 的 POSIX 语义） | 规范化的结果 | 卷与根目录按原样开头（0.19.2） |
 
 ### `libcxx/src/filesystem/path_parser.h` 与 `port/include/__filesystem/path.h` — 卷下的名字（0.19.1）
 
@@ -57,6 +58,13 @@ C 库（openkal-musl）在有卷的系统上把文件写作 `D:/...`，并像对
 - `__filesystem/path.h` 的 `append(Source)` 在 POSIX 分支只看首字符是否为分隔符；覆盖件在
   `OPENKAL` 或 `__OPENKAL__` 下改用 `path::is_absolute()` 判断，使 `path / "D:/y"` 与
   `path / path("D:/y")` 结果相同。头文件按本文的约定放在 `port/include/` 覆盖，vendored 树不动。
+- 0.19.2：`X:` 只有后跟分隔符时才是根名，而 `lexically_normal` 逐段用 `/=` 重建结果：`D:` 被当作
+  普通名字，随后的根目录 `/` 按 POSIX 语义替换了它，`D:/a/./b` 变成 `/a/b`；以它收尾的
+  `weakly_canonical` 同样丢卷。Windows 上经托管方式运行的程序因此把文件名放到了卷之外，启动器
+  无法启动其运行器（mcpp-community/mcpp#889）。`path.cpp` 的 `lexically_normal` 在 `OPENKAL` 下
+  以原样的卷与根目录开头（原地标记）；覆盖件的 `operator/=` 与两个 `append` 在追加“有根目录、
+  无根名”的名字时保留本身的卷（`D:/a` / `/b` 为 `D:/b`），与 [fs.path.append] 对有根名系统的规定
+  一致。
 
 ### `libcxx/src/atomic.cpp` — `std::atomic` 的等待与唤醒
 
diff --git a/llvm/libcxx/src/filesystem/path.cpp b/llvm/libcxx/src/filesystem/path.cpp
index 400b6e89..b12f8e2e 100644
--- a/llvm/libcxx/src/filesystem/path.cpp
+++ b/llvm/libcxx/src/filesystem/path.cpp
@@ -224,8 +224,28 @@ path path::lexically_normal() const {
 
   path Result;
   Result.__pn_.reserve(Parts.size() + NewPathSize + NeedTrailingSep);
+// ─── openkal ─── BEGIN ────────────────────────────────────────────────────────
+#if defined(OPENKAL)
+  // openkal: THE VOLUME AND ITS ROOT DIRECTORY BEGIN THE RESULT AS WRITTEN.
+  //
+  // `X:` is a root name only with the separator after it (path_parser.h), so
+  // appended part by part `D:` was an ordinary name and the root directory
+  // `/` replaced it: `D:/a/./b`.lexically_normal() was `/a/b`, and
+  // weakly_canonical, which ends in it, lost the volume the same way
+  // (0.19.2; mcpp-community/mcpp#889).
+  size_t First = 0;
+  if (Parts.size() >= 2 && Parts[1].second == PK_RootSep && has_root_name()) {
+    Result.__pn_ += Parts[0].first;
+    Result.__pn_ += Parts[1].first;
+    First = 2;
+  }
+  for (size_t I = First; I < Parts.size(); ++I)
+    Result /= Parts[I].first;
+#else
   for (auto& PK : Parts)
     Result /= PK.first;
+#endif
+// ─── openkal ─── END ──────────────────────────────────────────────────────────
 
   if (NeedTrailingSep)
     Result /= PATHSTR("");
diff --git a/mcpp.toml b/mcpp.toml
index 7faa78e9..3d8d864a 100644
--- a/mcpp.toml
+++ b/mcpp.toml
@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-llvm-runtime"
-version     = "0.19.1"
+version     = "0.19.2"
 description = "LLVM's C++ runtime libraries — libc++, libc++abi and libunwind — configured for openkal-musl rather than for a host C library."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]
diff --git a/port/include/__filesystem/path.h b/port/include/__filesystem/path.h
index c14d318b..423042a8 100644
--- a/port/include/__filesystem/path.h
+++ b/port/include/__filesystem/path.h
@@ -510,7 +510,34 @@ class _LIBCPP_EXPORTED_FROM_ABI path {
     return operator/=(path(__first, __last));
   }
 #  else
+#    if defined(OPENKAL) || defined(__OPENKAL__)
+  // openkal: A NAME BENEATH A VOLUME KEEPS ITS VOLUME (0.19.2).
+  //
+  // Appending a name that has a root directory and no root name (`/b`) to a
+  // name beneath a volume (`D:/a`) replaces the root directory and the
+  // relative path, and keeps the volume: `D:/b`, as [fs.path.append] states it
+  // for a system with root names. Taken as the whole name, `/` lost the
+  // volume in every builder that appends element by element:
+  // `D:/a/b`.lexically_normal() was `/a/b`, and so was a name that
+  // weakly_canonical and relative rebuild (0.19.1 made `X:/` a root name,
+  // openkal-llvm-runtime#64; mcpp-community/mcpp#889 found the loss).
+  _LIBCPP_HIDE_FROM_ABI bool __openkal_keep_volume(const path& __p) {
+    if (!__p.__root_name().empty() || __p.__root_directory().empty())
+      return false;
+    const __string_view __volume = __root_name();
+    if (__volume.empty())
+      return false;
+    string_type __whole(__volume);
+    __whole += __p.__pn_;
+    __pn_ = std::move(__whole);
+    return true;
+  }
+#    endif
   _LIBCPP_HIDE_FROM_ABI path& operator/=(const path& __p) {
+#    if defined(OPENKAL) || defined(__OPENKAL__)
+    if (__openkal_keep_volume(__p))
+      return *this;
+#    endif
     if (__p.is_absolute()) {
       __pn_ = __p.__pn_;
       return *this;
@@ -543,6 +570,8 @@ class _LIBCPP_EXPORTED_FROM_ABI path {
         __pn_ = std::move(__whole.__pn_);
         return *this;
       }
+    } else if (__openkal_keep_volume(path(__src))) {
+      return *this;
     }
 #    endif
     if (__source_is_absolute)
@@ -558,6 +587,10 @@ class _LIBCPP_EXPORTED_FROM_ABI path {
     typedef typename iterator_traits<_InputIt>::value_type _ItVal;
     static_assert(__can_convert_char<_ItVal>::value, "Must convertible");
     using _CVT = _PathCVT<_ItVal>;
+#    if defined(OPENKAL) || defined(__OPENKAL__)
+    if (__first != __last && filesystem::__is_separator(*__first) && __openkal_keep_volume(path(__first, __last)))
+      return *this;
+#    endif
     if (__first != __last && filesystem::__is_separator(*__first))
       __pn_.clear();
     else if (has_filename())