MinGW-W64-builds-4.2.0 shell doesn't like the empty else blocks.
@ -155,7 +155,7 @@ if test "x$want_boost" = "xyes"; then
AC_MSG_RESULT(yes)
succeeded=yes
found_system=yes
],[
],[:
])
AC_LANG_POP([C++])
@ -238,7 +238,7 @@ if test "x$want_boost" = "xyes"; then
fi