build_external is the only file used here, to build the external
packages of NCL. It's a mess as it's just a giant c-shell
script that has blocks of builds for each external
package.

----------------------------------------------------------------------
cairo notes: There's a PNG bug with cairo 1.12.16 and earlier, so use
cairo-1.10.2 instead.

It's important to use the correct versions of pixman, fontconfig, and
freetype with cairo. I think freetype is especially important, and
maybe pixman too.

I usually check which version of cairo is the latest, see what the
date is on it, and then make sure I don't update later dates of
freetype and fontconfig. The cairo download site usually has pixman
included with it, so I tend to use this.

Rick suggests using the system fontconfig rather than a
specially-built one.
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NetCDF-4 notes: Unidata provides versions of HDF5 and zlib with its
NetCDF-4 source, so I recommend using this.
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HDFEOS notes: Both hdfeos and hdfeos5 source codes have issues
with the Gctp "cproj.c" file which defines "sign". This conflicts with
some other "sign" defintion. You may have to edit cproj.c and change
"sign" to "cproj_sign".
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g2clib notes: we found a bug with g2clib-1.4.0-patch on 12/17/13 
(see JIRA NCL-1868). Use 1.2.3-patch instead.
----------------------------------------------------------------------
See the "wget_commands" file in this directory for the wget commands
used to retrieve all this software:

Here are the versions I use for everything:

    cairo-1.10.2
    curl-7.33.0
    esmf-6.2.0
    expat-2.1.0
    freetype-2.5.0.1
    g2clib-1.2.3-patch
    gdal-1.10.1
    hdf-4.2.9
    hdf5-1.8.11
    hdfeos-2.18
    hdfeos5-1.14
    jasper-1.900.1
    jpeg-6b
    libpng-1.2.50
    netcdf-4.3.0
    pixman-0.30.0
    szip-2.1
    zlib-1.2.8
    proj-4.8.0
    
    netcdf-cxx-4.2 (for ESMF only)
    netcdf-fortran-4.2 (for ESMF only)

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