diff --git a/plugins/python-build/bin/python-build b/plugins/python-build/bin/python-build
index 03f03ec4..661f4371 100755
--- a/plugins/python-build/bin/python-build
+++ b/plugins/python-build/bin/python-build
@@ -106,7 +106,7 @@ os_information() {
   if type -p lsb_release >/dev/null; then
     lsb_release -sir | xargs echo
   elif type -p sw_vers >/dev/null; then
-    echo "OS X $(sw_vers -productVersion)"
+    echo "OS X ${_PYTHON_BUILD_CACHE_SW_VERS:=$(sw_vers -productVersion)}"
   elif [ -r /etc/os-release ]; then
     source /etc/os-release
     echo "$NAME" $VERSION_ID
@@ -117,7 +117,7 @@ os_information() {
 }
 
 is_mac() {
-  [ "$(uname -s)" = "Darwin" ] || return 1
+  [ "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" = "Darwin" ] || return 1
   [ $# -eq 0 ] || [ "$(osx_version)" "$@" ]
 }
 
@@ -140,7 +140,7 @@ can_use_homebrew() {
 # 10.10 -> 1010
 osx_version() {
   local -a ver
-  IFS=. ver=( `sw_vers -productVersion` )
+  IFS=. ver=( ${_PYTHON_BUILD_CACHE_SW_VERS:=$(sw_vers -productVersion)} )
   IFS="$OLDIFS"
   echo $(( ${ver[0]}*100 + ${ver[1]} ))
 }
@@ -179,7 +179,7 @@ file_is_not_empty() {
 
 num_cpu_cores() {
   local num
-  case "$(uname -s)" in
+  case "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" in
   Darwin | *BSD )
     num="$(sysctl -n hw.ncpu 2>/dev/null || true)"
     ;;
@@ -971,7 +971,7 @@ build_package_micropython() {
 }
 
 pypy_architecture() {
-  case "$(uname -s)" in
+  case "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" in
   "Darwin" )
     case "$(uname -m)" in
     "arm64" ) echo "osarm64" ;;
@@ -1003,7 +1003,7 @@ pypy_architecture() {
 }
 
 graalpy_architecture() {
-  case "$(uname -s)" in
+  case "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" in
   "Darwin" )
     case "$(uname -m)" in
     "x86_64" ) echo "macos-amd64" ;;
@@ -1084,7 +1084,7 @@ build_package_pypy_builder() {
 }
 
 activepython_architecture() {
-  case "$(uname -s)" in
+  case "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" in
   "Darwin" ) echo "macosx10.9-i386-x86_64" ;;
   "Linux" )
     case "$(uname -m)" in
@@ -1104,7 +1104,7 @@ build_package_activepython() {
 }
 
 anaconda_architecture() {
-  case "$(uname -s)" in
+  case "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" in
   "Darwin" )
     case "$(uname -m)" in
     "arm64" ) echo "MacOSX-arm64" ;;
@@ -1381,7 +1381,7 @@ require_osx_version() {
   function version { echo "$@" | awk -F. '{ printf("%d%03d%03d%03d\n", $1,$2,$3,$4); }'; }
 
   local required_version="$@"
-  local osx_version="$(sw_vers -productVersion)"
+  local osx_version="${_PYTHON_BUILD_CACHE_SW_VERS:=$(sw_vers -productVersion)}"
   if [[ $(version $osx_version) -ge $(version $required_version) ]]; then
     return 0
   fi
@@ -1457,14 +1457,14 @@ use_homebrew_yaml() {
 
 use_freebsd_pkg() {
   # check if FreeBSD
-  if [ "FreeBSD" = "$(uname -s)" ]; then
+  if [ "FreeBSD" = "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" ]; then
     # use openssl if installed from Ports Collection
     if pkg info -e openssl; then
       package_option python configure --with-openssl="/usr/local"
     fi
 
     # check if 11-R or later
-    release="$(uname -r)"
+    release="${_PYTHON_BUILD_CACHE_UNAME_R:=$(uname -r)}"
     if [ "${release%%.*}" -ge 11 ]; then
       # Use packages from Ports Collection.
       #
@@ -2251,11 +2251,13 @@ if [ -n "$noexec" ]; then
 fi
 
 if [ -z "$MAKE" ]; then
-  if [ "FreeBSD" = "$(uname -s)" ]; then
+  if [ "FreeBSD" = "${_PYTHON_BUILD_CACHE_UNAME_S:=$(uname -s)}" ]; then
     if [ "$(echo $1 | sed 's/-.*$//')" = "jruby" ]; then
       export MAKE="gmake"
     else
-      if [ "$(uname -r | sed 's/[^[:digit:]].*//')" -lt 10 ]; then
+      # var assignment inside $() does not propagate due to being in subshell
+      : "${_PYTHON_BUILD_CACHE_UNAME_R:=$(uname -r)}"
+      if [ "$(echo "$_PYTHON_BUILD_CACHE_UNAME_R" | sed 's/[^[:digit:]].*//')" -lt 10 ]; then
         export MAKE="gmake"
       else
         export MAKE="make"
@@ -2450,7 +2452,7 @@ fi
 # Set MACOSX_DEPLOYMENT_TARGET from the product version of OS X (#219, #220)
 if is_mac; then
   if [ -z "${MACOSX_DEPLOYMENT_TARGET}" ]; then
-    MACOS_VERSION="$(sw_vers -productVersion 2>/dev/null || true)"
+    MACOS_VERSION="${_PYTHON_BUILD_CACHE_SW_VERS:=$(sw_vers -productVersion)}"
     MACOS_VERSION_ARRAY=(${MACOS_VERSION//\./ })
     if [ "${#MACOS_VERSION_ARRAY[@]}" -ge 2 ]; then
       export MACOSX_DEPLOYMENT_TARGET="${MACOS_VERSION_ARRAY[0]}.${MACOS_VERSION_ARRAY[1]}"
diff --git a/plugins/python-build/test/build.bats b/plugins/python-build/test/build.bats
index 8e3ce566..b0b054cf 100644
--- a/plugins/python-build/test/build.bats
+++ b/plugins/python-build/test/build.bats
@@ -62,7 +62,7 @@ assert_build_log() {
   cached_tarball "yaml-0.1.6"
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub brew false
   stub_make_install
   stub_make_install
@@ -104,7 +104,7 @@ OUT
   cached_tarball "yaml-0.1.6" "$yaml_configure"
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub brew false
   stub_make_install
   stub_make_install "$PYTHON_MAKE_INSTALL_TARGET"
@@ -132,7 +132,7 @@ OUT
   cached_tarball "yaml-0.1.6"
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub brew false
   stub_make_install
   stub_make_install
@@ -162,7 +162,7 @@ OUT
   cached_tarball "yaml-0.1.6"
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub brew false
   stub_make_install
   stub_make_install
@@ -194,8 +194,8 @@ OUT
   BREW_PREFIX="$TMP/homebrew-prefix"
   mkdir -p "$BREW_PREFIX"
 
-  for i in {1..9}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
   stub brew "--prefix : echo '$BREW_PREFIX'" false
   stub_make_install
 
@@ -222,8 +222,8 @@ OUT
   brew_libdir="$TMP/homebrew-yaml"
   mkdir -p "$brew_libdir"
 
-  for i in {1..10}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
   stub brew "--prefix libyaml : echo '$brew_libdir'"
   for i in {1..6}; do stub brew false; done
   stub_make_install
@@ -249,8 +249,8 @@ OUT
 
   readline_libdir="$TMP/homebrew-readline"
   mkdir -p "$readline_libdir"
-  for i in {1..8}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
   for i in {1..3}; do stub brew false; done
   stub brew "--prefix readline : echo '$readline_libdir'"
   for i in {1..2}; do stub brew false; done
@@ -279,8 +279,8 @@ OUT
 
   ncurses_libdir="$TMP/homebrew-ncurses"
   mkdir -p "$ncurses_libdir"
-  for i in {1..9}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
   for i in {1..4}; do stub brew false; done
   stub brew "--prefix ncurses : echo '$ncurses_libdir'"
   stub brew false
@@ -307,9 +307,8 @@ OUT
 @test "openssl is linked from Ports in FreeBSD if present" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..7}; do stub uname '-s : echo FreeBSD'; done
+  stub uname '-s : echo FreeBSD'
   stub uname '-r : echo 11.0-RELEASE'
-  for i in {1..3}; do stub uname '-s : echo FreeBSD'; done
   stub sysctl '-n hw.ncpu : echo 1'
 
   stub pkg "info -e openssl : true"
@@ -341,9 +340,8 @@ OUT
 
   for lib in readline sqlite3; do
 
-    for i in {1..7}; do stub uname '-s : echo FreeBSD'; done
+    stub uname '-s : echo FreeBSD'
     stub uname '-r : echo 11.0-RELEASE'
-    for i in {1..3}; do stub uname '-s : echo FreeBSD'; done
     stub sysctl '-n hw.ncpu : echo 1'
 
     stub pkg false
@@ -376,8 +374,8 @@ OUT
 @test "homebrew is not touched if PYTHON_BUILD_SKIP_HOMEBREW is set" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..4}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
   stub brew true; brew
   stub_make_install
   export PYTHON_BUILD_SKIP_HOMEBREW=1
@@ -405,7 +403,7 @@ OUT
   BREW_PREFIX="$TMP/homebrew-prefix"
   mkdir -p "$BREW_PREFIX"
 
-  for i in {1..4}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub brew "--prefix : echo '$BREW_PREFIX'"
   for i in {1..5}; do stub brew false; done
   stub_make_install
@@ -435,7 +433,7 @@ OUT
   BREW_PREFIX="${BREW_PREFIX%/*}"
   BREW_PREFIX="${BREW_PREFIX%/*}"
 
-  for i in {1..4}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub brew "--prefix : echo '$BREW_PREFIX'"
   for i in {1..5}; do stub brew false; done
   stub_make_install
@@ -464,7 +462,7 @@ OUT
   BREW_PREFIX="$TMP/homebrew-prefix"
   mkdir -p "$BREW_PREFIX"
 
-  for i in {1..9}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   for i in {1..5}; do stub brew "--prefix : echo '$BREW_PREFIX'"; done
   stub_make_install
 
@@ -493,8 +491,8 @@ OUT
   mkdir -p "$readline_libdir/include/readline"
   touch "$readline_libdir/include/readline/rlconf.h"
 
-  for i in {1..8}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
 
   for i in {1..5}; do stub brew false; done
   stub_make_install
@@ -525,8 +523,8 @@ OUT
   mkdir -p "$tcl_tk_libdir/lib"
   echo "TCL_VERSION='$tcl_tk_version'" >>"$tcl_tk_libdir/lib/tclConfig.sh"
 
-  for i in {1..9}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
 
   stub brew false
   stub brew "--prefix tcl-tk@8 : echo '$tcl_tk_libdir'"
@@ -559,8 +557,8 @@ OUT
   tcl_tk_version_long="8.6.10"
   tcl_tk_version="${tcl_tk_version_long%.*}"
 
-  for i in {1..8}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
 
   for i in {1..4}; do stub brew false; done
   stub_make_install
@@ -587,8 +585,8 @@ OUT
 @test "tcl-tk is linked from Homebrew via pkgconfig only when envvar is set" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..9}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
 
   tcl_tk_libdir="$TMP/homebrew-tcl-tk"
   mkdir -p "$tcl_tk_libdir/lib"
@@ -620,8 +618,8 @@ OUT
 @test "number of CPU cores defaults to 2" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 10.10'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
 
   stub sysctl false
   stub_make_install
@@ -647,8 +645,8 @@ OUT
 @test "number of CPU cores is detected on Mac" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 10.10'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
 
   stub sysctl '-n hw.ncpu : echo 4'
   stub_make_install
@@ -675,9 +673,8 @@ OUT
 @test "number of CPU cores is detected on FreeBSD" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..7}; do stub uname '-s : echo FreeBSD'; done
+  stub uname '-s : echo FreeBSD'
   stub uname '-r : echo 11.0-RELEASE'
-  for i in {1..3}; do stub uname '-s : echo FreeBSD'; done
   for i in {1..3}; do stub pkg false; done
 
   stub sysctl '-n hw.ncpu : echo 1'
@@ -704,7 +701,7 @@ OUT
 @test "setting PYTHON_MAKE_INSTALL_OPTS to a multi-word string" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..9}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
 
   stub_make_install
 
@@ -728,7 +725,7 @@ OUT
 @test "--enable-shared is not added if --disable-shared is passed" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..9}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
 
   stub_make_install
 
@@ -752,8 +749,8 @@ OUT
 @test "configuring with dSYM in MacOS" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 1010'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 1010'
   for i in {1..6}; do stub brew false; done
   stub_make_install
 
@@ -779,7 +776,7 @@ OUT
 @test "configuring with dSYM has no effect in non-MacOS" {
   cached_tarball "Python-3.6.2"
 
-  for i in {1..10}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub_make_install
 
   run_inline_definition <<DEF
@@ -811,10 +808,8 @@ OUT
 @test "make on FreeBSD 9 defaults to gmake" {
   cached_tarball "Python-3.6.2"
 
-  stub uname "-s : echo FreeBSD" "-r : echo 9.1"
-  for i in {1..6}; do stub uname "-s : echo FreeBSD"; done
+  stub uname "-s : echo FreeBSD"
   stub uname "-r : echo 9.1"
-  for i in {1..3}; do stub uname "-s : echo FreeBSD"; done
 
   MAKE=gmake stub_make_install
 
@@ -828,10 +823,8 @@ OUT
 @test "make on FreeBSD 10" {
   cached_tarball "Python-3.6.2"
 
-  stub uname "-s : echo FreeBSD" "-r : echo 10.0-RELEASE"
-  for i in {1..6}; do stub uname "-s : echo FreeBSD"; done
+  stub uname "-s : echo FreeBSD"
   stub uname "-r : echo 10.0-RELEASE"
-  for i in {1..3}; do stub uname "-s : echo FreeBSD"; done
 
   stub_make_install
 
@@ -844,10 +837,8 @@ OUT
 @test "make on FreeBSD 11" {
   cached_tarball "Python-3.6.2"
 
-  stub uname "-s : echo FreeBSD" "-r : echo 11.0-RELEASE"
-  for i in {1..6}; do stub uname "-s : echo FreeBSD"; done
+  stub uname "-s : echo FreeBSD"
   stub uname "-r : echo 11.0-RELEASE"
-  for i in {1..3}; do stub uname "-s : echo FreeBSD"; done
 
   stub_make_install
 
@@ -866,7 +857,7 @@ apply -p1 -i /my/patch.diff
 exec ./configure "\$@"
 CONF
 
-  for i in {1..9}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub apply 'echo apply "$@" >> build.log'
   stub_make_install
 
diff --git a/plugins/python-build/test/compiler.bats b/plugins/python-build/test/compiler.bats
index 61ff22be..9ca1735c 100644
--- a/plugins/python-build/test/compiler.bats
+++ b/plugins/python-build/test/compiler.bats
@@ -9,8 +9,8 @@ export -n PYTHON_CONFIGURE_OPTS
 
 @test "require_gcc on OS X 10.9" {
 
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 10.9.5'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.9.5'
 
   stub gcc '--version : echo 4.2.1'
 
@@ -31,8 +31,8 @@ OUT
 }
 
 @test "require_gcc on OS X 10.10" {
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 10.10'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
 
   stub gcc '--version : echo 4.2.1'
 
@@ -69,8 +69,8 @@ DEF
   mkdir -p "$INSTALL_ROOT"
   cd "$INSTALL_ROOT"
 
-  for i in {1..10}; do stub uname '-s : echo Darwin'; done
-  for i in {1..3}; do stub sw_vers '-productVersion : echo 10.10'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
 
   stub cc 'false'
   stub brew 'false'
diff --git a/plugins/python-build/test/pyenv_ext.bats b/plugins/python-build/test/pyenv_ext.bats
index a4d45901..1c4b47a7 100644
--- a/plugins/python-build/test/pyenv_ext.bats
+++ b/plugins/python-build/test/pyenv_ext.bats
@@ -144,7 +144,7 @@ OUT
   echo "bar" | install_patch definitions/vanilla-python "Python-3.6.2/bar.patch"
   echo "baz" | install_patch definitions/vanilla-python "Python-3.6.2/baz.patch"
 
-  for i in {1..2}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
 
   TMPDIR="$TMP" install_tmp_fixture definitions/vanilla-python < /dev/null
   assert_success
@@ -171,7 +171,7 @@ OUT
     " : echo \"$MAKE \$@\" >> build.log" \
     " : echo \"$MAKE \$@\" >> build.log && cat build.log >> '$INSTALL_ROOT/build.log'"
 
-  for i in {1..4}; do stub uname '-s : echo Darwin'; done
+  stub uname '-s : echo Darwin'
 
   PYTHON_MAKE_INSTALL_TARGET="altinstall" TMPDIR="$TMP" install_tmp_fixture definitions/vanilla-python < /dev/null
   assert_success
@@ -253,7 +253,8 @@ OUT
   done
   unset framework_path executable
 
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
 
   PYTHON_CONFIGURE_OPTS="--enable-framework" TMPDIR="$TMP" run_inline_definition <<OUT
 echo "PYTHON_CONFIGURE_OPTS_ARRAY=(\${PYTHON_CONFIGURE_OPTS_ARRAY[@]})"
@@ -274,7 +275,8 @@ EOS
 
 @test "enable universalsdk" {
   
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
   stub arch "echo x86_64"
 
   PYTHON_CONFIGURE_OPTS="--enable-universalsdk" TMPDIR="$TMP" run_inline_definition <<OUT
@@ -292,7 +294,8 @@ EOS
 
 @test "enable universalsdk on Apple Silicon" {
 
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 11.7'
   stub arch "echo arm64"
 
   PYTHON_CONFIGURE_OPTS="--enable-universalsdk" TMPDIR="$TMP" run_inline_definition <<OUT
@@ -310,7 +313,8 @@ EOS
 
 @test "enable universalsdk with explicit archs argument" {
 
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 11.7'
 
   PYTHON_CONFIGURE_OPTS="--enable-universalsdk --with-universal-archs=foo" TMPDIR="$TMP" run_inline_definition <<OUT
 echo "PYTHON_CONFIGURE_OPTS_ARRAY=(\${PYTHON_CONFIGURE_OPTS_ARRAY[@]})"
@@ -325,7 +329,7 @@ EOS
   cached_tarball "Python-3.6.2"
 
   for i in {1..4}; do stub brew false; done
-  for i in {1..8}; do stub uname '-s : echo Linux'; done
+  stub uname '-s : echo Linux'
   stub "$MAKE" \
     " : echo \"$MAKE \$@\" >> build.log" \
     " : echo \"$MAKE \$@\" >> build.log && cat build.log >> '$INSTALL_ROOT/build.log'"
@@ -346,8 +350,8 @@ OUT
 
 @test "default MACOSX_DEPLOYMENT_TARGET" {
   # yyuu/pyenv#257
-  for i in {1..3}; do stub uname '-s : echo Darwin'; done
-  for i in {1..2}; do stub sw_vers '-productVersion : echo 10.10'; done
+  stub uname '-s : echo Darwin'
+  stub sw_vers '-productVersion : echo 10.10'
 
   TMPDIR="$TMP" run_inline_definition <<OUT
 echo "\${MACOSX_DEPLOYMENT_TARGET}"