im6890hdri convert -version
Version: ImageMagick 6.8.9-0 Q16 x86_64 2014-04-23 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2014 ImageMagick Studio LLC
Features: DPC HDRI Modules OpenMP
Delegates: bzlib fftw fontconfig freetype gslib jbig jng jpeg lcms lqr ltdl lzma openexr png ps tiff webp x xml zlib
Using Mac Mini 2.66 GHz Core 2 Duo
-limit thread 2 works fine, but I get an error when limiting the threads to 1
im6890hdri convert -limit thread 1 grad.png +fft +ift null:
Assertion failed: (id < (int) cache_view->number_threads), function GetCacheViewVirtualPixels, file magick/cache-view.c, line 730.
Abort trap