[gmx-users] Gromacs GMX_BUILD_FFTW warning in building Gromas 5.0.4

[Justin Lemkul]

On 10/6/16 1:34 PM, Steve Seibold wrote:
>
> HelloI have been attempting to compile and build Gromacs 5.0.4for a couple of
> weeks. I have been following the instructions (having also readGromacs 5.0
> instruction in Manual..) at
> https://ourphysics.org/wiki/index.php/How_to_compile_Gromacs#Gromacs_5.1.1_MPI.2C_single
> Specifically, I have used “Gromacs 5.0.4 MPI, Single, GPU”instructions at
> this site; however, without the “GPU” part.. I have both OpenMPI and
> FFTW-3.2.2 in the standardlocations. In the screen output when I use CMake to
> compile, I get the message that “can’t locate fftw3fmodule” . However, the
> configurations is done and the build files are made;however, I also get the
> message “CMake warning that manually-specified variableswere not use by the
> project: GMX_BUILD_FFTW” Does this mean FFTW is disabled????? Not sure.. I
> made sure that I was using the correct version of CMakewhich is CMake-3.5.2
> and the correct FFTW-3.2.2,,, I did find on line where someone online said if
> they reconfiguredFFTW with  "--enable-float" that theysolved the problem of
> “can’tlocate fftw3f module”; but this was for Gromacs 4.5 and there is no
> realexplanation. So, I am hesitant to try this….. Any information would be
> extremely helpful!!! Thanks Steve
>

Please make sure your emails have sensible line breaks; this is very hard to read.

What you're observing is that "GMX_BUILD_FFTW" is not a valid argument.  It's 
"GMX_BUILD_OWN_FFTW" and that's only needed if you want GROMACS to build FFTW 
for you.  Since you already built FFTW (although 3.2.2 is utterly ancient, so 
you should get the latest version, i.e. 3.3.5) then you don't need this option. 
This is confirmed by the fact that, as you say, configuration completes.  If 
cmake can't find a suitable FFTW, it will throw a fatal error.

-Justin

-- 
==================================================

Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

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