diff --git a/configure b/configure
index 3c2a9cf0a249dd..fe625488592198 100755
--- a/configure
+++ b/configure
@@ -3770,91 +3770,97 @@ _ACEOF
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking MACHDEP" >&5
 $as_echo_n "checking MACHDEP... " >&6; }
-if test -z "$MACHDEP"
-then
-    # avoid using uname for cross builds
-    if test "$cross_compiling" = yes; then
-       # ac_sys_system and ac_sys_release are used for setting
-       # a lot of different things including 'define_xopen_source'
-       # in the case statement below.
-	case "$host" in
-	*-*-linux-android*)
-		ac_sys_system=Linux-android
-		;;
-	*-*-linux*)
-		ac_sys_system=Linux
-		;;
-	*-*-cygwin*)
-		ac_sys_system=Cygwin
-		;;
-	*-*-vxworks*)
-	    ac_sys_system=VxWorks
-	    ;;
-	*-*-emscripten)
-	    ac_sys_system=Emscripten
-	    ;;
-	*-*-wasi)
-	    ac_sys_system=WASI
-	    ;;
-	*)
-		# for now, limit cross builds to known configurations
-		MACHDEP="unknown"
-		as_fn_error $? "cross build not supported for $host" "$LINENO" 5
-	esac
-	ac_sys_release=
-    else
-	ac_sys_system=`uname -s`
-	if test "$ac_sys_system" = "AIX" \
-	-o "$ac_sys_system" = "UnixWare" -o "$ac_sys_system" = "OpenUNIX"; then
-		ac_sys_release=`uname -v`
-	else
-		ac_sys_release=`uname -r`
-	fi
-    fi
-    ac_md_system=`echo $ac_sys_system |
-			tr -d '/ ' | tr '[A-Z]' '[a-z]'`
-    ac_md_release=`echo $ac_sys_release |
-			tr -d '/ ' | sed 's/^[A-Z]\.//' | sed 's/\..*//'`
-    MACHDEP="$ac_md_system$ac_md_release"
-
-    case $MACHDEP in
-	aix*) MACHDEP="aix";;
-	linux*) MACHDEP="linux";;
-	cygwin*) MACHDEP="cygwin";;
-	darwin*) MACHDEP="darwin";;
-	'')	MACHDEP="unknown";;
-    esac
+if ${MACHDEP+:} false; then :
+
+else
+
+    if test "x$cross_compiling" = xyes; then :
+
+                case $host in #(
+  *-*-linux-android*) :
+    ac_sys_system=Linux-android ;; #(
+  *-*-linux*) :
+    ac_sys_system=Linux ;; #(
+  *-*-cygwin*) :
+    ac_sys_system=Cygwin ;; #(
+  *-*-vxworks*) :
+    ac_sys_system=VxWorks ;; #(
+  *-*-emscripten) :
+    ac_sys_system=Emscripten ;; #(
+  *-*-wasi) :
+    ac_sys_system=WASI ;; #(
+  *) :
+            MACHDEP="unknown"
+        as_fn_error $? "cross build not supported for $host" "$LINENO" 5
+
+     ;;
+esac
+    ac_sys_release=
+
+else
+
+    ac_sys_system=$(uname -s)
+    case $ac_sys_system in #(
+  AIX|UnixWare|OpenUNIX) :
+    ac_sys_release=$(uname -v) ;; #(
+  *) :
+    ac_sys_release=$(uname -r)
+     ;;
+esac
+
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: \"$MACHDEP\"" >&5
-$as_echo "\"$MACHDEP\"" >&6; }
+  ac_md_system=$(echo $ac_sys_system | tr -d '/ ' | tr '[A-Z]' '[a-z]')
+  ac_md_release=$(echo $ac_sys_release | tr -d '/ ' | sed 's/^[A-Z]\.//' | sed 's/\..*//')
+  MACHDEP="$ac_md_system$ac_md_release"
+
+  case $MACHDEP in #(
+  aix*) :
+    MACHDEP="aix" ;; #(
+  linux*) :
+    MACHDEP="linux" ;; #(
+  cygwin*) :
+    MACHDEP="cygwin" ;; #(
+  darwin*) :
+    MACHDEP="darwin" ;; #(
+  '') :
+    MACHDEP="unknown"
+   ;; #(
+  *) :
+     ;;
+esac
 
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $MACHDEP" >&5
+$as_echo "$MACHDEP" >&6; }
+
+
+if test "x$cross_compiling" = xyes; then :
+
+  case $host in #(
+  *-*-linux*) :
+
+      case $host_cpu in #(
+  arm*) :
+    _host_cpu=arm ;; #(
+  *) :
+    _host_cpu=$host_cpu
+       ;;
+esac
+     ;; #(
+  *-*-cygwin*) :
+    _host_cpu= ;; #(
+  *-*-vxworks*) :
+    _host_cpu=$host_cpu ;; #(
+  wasm32-*-*|wasm64-*-*) :
+    _host_cpu=$host_cpu ;; #(
+  *) :
+          MACHDEP="unknown"
+      as_fn_error $? "cross build not supported for $host" "$LINENO" 5
+
+   ;;
+esac
+  _PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
 
-if test "$cross_compiling" = yes; then
-	case "$host" in
-	*-*-linux*)
-		case "$host_cpu" in
-		arm*)
-			_host_cpu=arm
-			;;
-		*)
-			_host_cpu=$host_cpu
-		esac
-		;;
-	*-*-cygwin*)
-		_host_cpu=
-		;;
-	*-*-vxworks*)
-		_host_cpu=$host_cpu
-		;;
-	wasm32-*-* | wasm64-*-*)
-		_host_cpu=$host_cpu
-		;;
-	*)
-		# for now, limit cross builds to known configurations
-		MACHDEP="unknown"
-		as_fn_error $? "cross build not supported for $host" "$LINENO" 5
-	esac
-	_PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
 fi
 
 # Some systems cannot stand _XOPEN_SOURCE being defined at all; they
@@ -6169,7 +6175,7 @@ if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ANDROID_API_LEVEL" >&5
 $as_echo "$ANDROID_API_LEVEL" >&6; }
   if test -z "$ANDROID_API_LEVEL"; then
-    as_fn_error $? "Fatal: you must define __ANDROID_API__" "$LINENO" 5
+    as_fn_error $? "you must define __ANDROID_API__" "$LINENO" 5
   fi
 
 cat >>confdefs.h <<_ACEOF
diff --git a/configure.ac b/configure.ac
index fa5e63cf5c3f98..0a1e07ed7e1a6e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -487,92 +487,66 @@ AC_DEFINE_UNQUOTED(_PYTHONFRAMEWORK, "${PYTHONFRAMEWORK}", [framework name])
 
 # Set name for machine-dependent library files
 AC_ARG_VAR([MACHDEP], [name for machine-dependent library files])
-AC_MSG_CHECKING(MACHDEP)
-if test -z "$MACHDEP"
-then
-    # avoid using uname for cross builds
-    if test "$cross_compiling" = yes; then
-       # ac_sys_system and ac_sys_release are used for setting
-       # a lot of different things including 'define_xopen_source'
-       # in the case statement below.
-	case "$host" in
-	*-*-linux-android*)
-		ac_sys_system=Linux-android
-		;;
-	*-*-linux*)
-		ac_sys_system=Linux
-		;;
-	*-*-cygwin*)
-		ac_sys_system=Cygwin
-		;;
-	*-*-vxworks*)
-	    ac_sys_system=VxWorks
-	    ;;
-	*-*-emscripten)
-	    ac_sys_system=Emscripten
-	    ;;
-	*-*-wasi)
-	    ac_sys_system=WASI
-	    ;;
-	*)
-		# for now, limit cross builds to known configurations
-		MACHDEP="unknown"
-		AC_MSG_ERROR([cross build not supported for $host])
-	esac
-	ac_sys_release=
-    else
-	ac_sys_system=`uname -s`
-	if test "$ac_sys_system" = "AIX" \
-	-o "$ac_sys_system" = "UnixWare" -o "$ac_sys_system" = "OpenUNIX"; then
-		ac_sys_release=`uname -v`
-	else
-		ac_sys_release=`uname -r`
-	fi
-    fi
-    ac_md_system=`echo $ac_sys_system |
-			tr -d '[/ ]' | tr '[[A-Z]]' '[[a-z]]'`
-    ac_md_release=`echo $ac_sys_release |
-			tr -d '[/ ]' | sed 's/^[[A-Z]]\.//' | sed 's/\..*//'`
-    MACHDEP="$ac_md_system$ac_md_release"
-
-    case $MACHDEP in
-	aix*) MACHDEP="aix";;
-	linux*) MACHDEP="linux";;
-	cygwin*) MACHDEP="cygwin";;
-	darwin*) MACHDEP="darwin";;
-	'')	MACHDEP="unknown";;
-    esac
-fi
-AC_MSG_RESULT("$MACHDEP")
+AC_MSG_CHECKING([MACHDEP])
+AS_VAR_SET_IF([MACHDEP], [], [
+  dnl Avoid using uname for cross builds.
+  AS_VAR_IF([cross_compiling], [yes], [
+    dnl ac_sys_system and ac_sys_release are used for setting
+    dnl a lot of different things including 'define_xopen_source'
+    dnl in the case statement below.
+    AS_CASE([$host],
+      [*-*-linux-android*], [ac_sys_system=Linux-android],
+      [*-*-linux*],         [ac_sys_system=Linux],
+      [*-*-cygwin*],        [ac_sys_system=Cygwin],
+      [*-*-vxworks*],       [ac_sys_system=VxWorks],
+      [*-*-emscripten],     [ac_sys_system=Emscripten],
+      [*-*-wasi],           [ac_sys_system=WASI],
+      [dnl For now, limit cross builds to known configurations.
+        MACHDEP="unknown"
+        AC_MSG_ERROR([cross build not supported for $host])
+      ]
+    )
+    ac_sys_release=
+  ], [
+    ac_sys_system=$(uname -s)
+    AS_CASE([$ac_sys_system],
+      [AIX|UnixWare|OpenUNIX], [ac_sys_release=$(uname -v)],
+      [ac_sys_release=$(uname -r)]
+    )
+  ])
+  ac_md_system=$(echo $ac_sys_system | tr -d '[/ ]' | tr '[[A-Z]]' '[[a-z]]')
+  ac_md_release=$(echo $ac_sys_release | tr -d '[/ ]' | sed 's/^[[A-Z]]\.//' | sed 's/\..*//')
+  MACHDEP="$ac_md_system$ac_md_release"
+
+  AS_CASE([$MACHDEP],
+    [aix*],    [MACHDEP="aix"],
+    [linux*],  [MACHDEP="linux"],
+    [cygwin*], [MACHDEP="cygwin"],
+    [darwin*], [MACHDEP="darwin"],
+    [''],      [MACHDEP="unknown"]
+  )
+])
+AC_MSG_RESULT([$MACHDEP])
 
 AC_SUBST(_PYTHON_HOST_PLATFORM)
-if test "$cross_compiling" = yes; then
-	case "$host" in
-	*-*-linux*)
-		case "$host_cpu" in
-		arm*)
-			_host_cpu=arm
-			;;
-		*)
-			_host_cpu=$host_cpu
-		esac
-		;;
-	*-*-cygwin*)
-		_host_cpu=
-		;;
-	*-*-vxworks*)
-		_host_cpu=$host_cpu
-		;;
-	wasm32-*-* | wasm64-*-*)
-		_host_cpu=$host_cpu
-		;;
-	*)
-		# for now, limit cross builds to known configurations
-		MACHDEP="unknown"
-		AC_MSG_ERROR([cross build not supported for $host])
-	esac
-	_PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
-fi
+AS_VAR_IF([cross_compiling], [yes], [
+  AS_CASE([$host],
+    [*-*-linux*], [
+      AS_CASE([$host_cpu],
+        [arm*], [_host_cpu=arm],
+        [_host_cpu=$host_cpu]
+      )
+    ],
+    [*-*-cygwin*], [_host_cpu=],
+    [*-*-vxworks*], [_host_cpu=$host_cpu],
+    [wasm32-*-*|wasm64-*-*], [_host_cpu=$host_cpu],
+    [dnl For now, limit cross builds to known configurations.
+      MACHDEP="unknown"
+      AC_MSG_ERROR([cross build not supported for $host])
+    ]
+  )
+  _PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
+])
 
 # Some systems cannot stand _XOPEN_SOURCE being defined at all; they
 # disable features if it is defined, without any means to access these
@@ -1037,7 +1011,7 @@ if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
   _arm_arch=`sed -n -e '/__ARM_ARCH/d' -e 's/^arm_arch = //p' conftest.out`
   AC_MSG_RESULT([$ANDROID_API_LEVEL])
   if test -z "$ANDROID_API_LEVEL"; then
-    AC_MSG_ERROR([Fatal: you must define __ANDROID_API__])
+    AC_MSG_ERROR([you must define __ANDROID_API__])
   fi
   AC_DEFINE_UNQUOTED(ANDROID_API_LEVEL, $ANDROID_API_LEVEL, [The Android API level.])