I cloned master branch on my HPC(centos) . (for MPAS-A ver-7)
set up env as in instructions .
than ran ./configure.ac --prefix=/usr/local/pio-2.4.2 --enable-fortran
got this
./configure.ac: line 5: syntax error near unexpected token pio,' ./configure.ac: line 5: AC_INIT(pio, 2.5.5)'
