Zowie

1. You have Ghostscript installed, right? Otherwise sudo apt-get install ghostscript
2. This is important and installs the headers (iapi.h etc) which are required but don't come with the default Ghostscript package: sudo apt-get install libgs-dev
3. I also needed sudo apt-get install gs-esp
4. For me the pre compiled version of ImageMagick never accepted Ghostscript, so let's remove it: sudo apt-get --purge remove imagemagick
5. Get the source of ImageMagick, untar it, cd ImageMagick-xx
6. ./configure --with-gslib=yes [and what else you need]
7. Confirm in the output near the bottom gslib yes yes and not gslib yes no
8. make
9. make install
10. Run convert -list configure | grep DELEGATES => DELEGATES bzlib djvu freetype gs jpeg jng jp2 lcms png tiff x11 xml zlib