diff --git a/Lib/sysconfig/__main__.py b/Lib/sysconfig/__main__.py
index bc2197cfe79402..b0c00175afd7e9 100644
--- a/Lib/sysconfig/__main__.py
+++ b/Lib/sysconfig/__main__.py
@@ -162,7 +162,7 @@ def _print_config_dict(d, stream):
 
 def _get_pybuilddir():
     pybuilddir = f'build/lib.{get_platform()}-{get_python_version()}'
-    if get_config_var('Py_DEBUG') == '1':
+    if get_config_var('Py_DEBUG'):
         pybuilddir += '-pydebug'
     return pybuilddir
 
diff --git a/Misc/NEWS.d/next/Library/2025-03-31-17-15-09.gh-issue-127405.E7lPpD.rst b/Misc/NEWS.d/next/Library/2025-03-31-17-15-09.gh-issue-127405.E7lPpD.rst
new file mode 100644
index 00000000000000..7a669b65c91d10
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-03-31-17-15-09.gh-issue-127405.E7lPpD.rst
@@ -0,0 +1 @@
+Remove dead code in function ``sysconfig._get_pybuilddir``. Patch by Xuehai Pan.
diff --git a/Tools/wasm/wasi.py b/Tools/wasm/wasi.py
index da847c4ff86215..caf233c5ac4061 100644
--- a/Tools/wasm/wasi.py
+++ b/Tools/wasm/wasi.py
@@ -296,7 +296,7 @@ def main():
                         # Make sure the stack size will work for a pydebug
                         # build.
                         # Use 16 MiB stack.
-                        "--wasm max-wasm-stack=16777216 "
+                        "--wasm max-wasm-stack=33554432 "
                         # Enable thread support; causes use of preview1.
                         #"--wasm threads=y --wasi threads=y "
                         # Map the checkout to / to load the stdlib from /Lib.
diff --git a/Tools/wasm/wasm_build.py b/Tools/wasm/wasm_build.py
index bcb80212362b71..9b6874a26e5448 100755
--- a/Tools/wasm/wasm_build.py
+++ b/Tools/wasm/wasm_build.py
@@ -329,10 +329,17 @@ def _check_wasi() -> None:
         # workaround for https://github.com/python/cpython/issues/95952
         "HOSTRUNNER": (
             "wasmtime run "
-            "--wasm max-wasm-stack=16777216 "
+            "--wasm max-wasm-stack=33554432 "
             "--wasi preview2 "
             "--dir {srcdir}::/ "
-            "--env PYTHONPATH=/{relbuilddir}/build/lib.wasi-wasm32-{version}:/Lib"
+            "--env PYTHONPATH="
+            + ":".join(
+                (
+                    "/{relbuilddir}/build/lib.wasi-wasm32-{version}-pydebug",
+                    "/{relbuilddir}/build/lib.wasi-wasm32-{version}",
+                    "/Lib",
+                )
+            )
         ),
         "PATH": [WASI_SDK_PATH / "bin", os.environ["PATH"]],
     },
diff --git a/configure b/configure
index a058553480ca5a..75dc073949c411 100755
--- a/configure
+++ b/configure
@@ -7886,7 +7886,7 @@ then :
 fi
      ;; #(
               WASI) :
-    HOSTRUNNER='wasmtime run --wasm max-wasm-stack=16777216 --wasi preview2=n --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --dir $(srcdir)::/' ;; #(
+    HOSTRUNNER='wasmtime run --wasm max-wasm-stack=33554432 --wasi preview2=n --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --dir $(srcdir)::/' ;; #(
   *) :
     HOSTRUNNER=''
    ;;
@@ -9699,7 +9699,7 @@ then :
 
 fi
 
-                as_fn_append LDFLAGS_NODIST " -z stack-size=16777216 -Wl,--stack-first -Wl,--initial-memory=41943040"
+                as_fn_append LDFLAGS_NODIST " -z stack-size=33554432 -Wl,--stack-first -Wl,--initial-memory=41943040"
 
  ;; #(
   *) :
@@ -35159,4 +35159,3 @@ if test "$ac_cv_header_stdatomic_h" != "yes"; then
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: Your compiler or platform does have a working C11 stdatomic.h. A future version of Python may require stdatomic.h." >&5
 printf "%s\n" "$as_me: Your compiler or platform does have a working C11 stdatomic.h. A future version of Python may require stdatomic.h." >&6;}
 fi
-
diff --git a/configure.ac b/configure.ac
index 23bd81ed4431b9..52d65ac3956995 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1638,7 +1638,7 @@ then
     dnl TODO: support other WASI runtimes
     dnl wasmtime starts the process with "/" as CWD. For OOT builds add the
     dnl directory containing _sysconfigdata to PYTHONPATH.
-    [WASI], [HOSTRUNNER='wasmtime run --wasm max-wasm-stack=16777216 --wasi preview2=n --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --dir $(srcdir)::/'],
+    [WASI], [HOSTRUNNER='wasmtime run --wasm max-wasm-stack=33554432 --wasi preview2=n --env PYTHONPATH=/$(shell realpath --relative-to $(abs_srcdir) $(abs_builddir))/$(shell cat pybuilddir.txt):/Lib --dir $(srcdir)::/'],
     [HOSTRUNNER='']
   )
 fi
@@ -2420,7 +2420,7 @@ AS_CASE([$ac_sys_system],
     dnl gh-117645: Set the memory size to 40 MiB, the stack size to 16 MiB,
     dnl and move the stack first.
     dnl https://github.com/WebAssembly/wasi-libc/issues/233
-    AS_VAR_APPEND([LDFLAGS_NODIST], [" -z stack-size=16777216 -Wl,--stack-first -Wl,--initial-memory=41943040"])
+    AS_VAR_APPEND([LDFLAGS_NODIST], [" -z stack-size=33554432 -Wl,--stack-first -Wl,--initial-memory=41943040"])
   ]
 )