AC_MSG_WARN([cannot find 'cython' program. You should look at http://www.cython.org] or install your distribution specific cython package.)
AC_MSG_WARN([Unable to find 'cython' or 'cython3' program. You should look at https://cython.org or install your distribution specific cython package.])
CYTHON=false
elif test -n "$1" ; then
AC_MSG_CHECKING([for Cython version])
...
...
@@ -59,7 +59,7 @@ AC_DEFUN([AC_PROG_CYTHON],[
CYTHON='echo "Error: Cython version >= $1 is required. You have '"$cython_version"'. You should look at http://www.cython.org" ; false'