Comment 4 for bug 929573

From the linked debian bug:
imagemagick is not supposed to use /usr/bin/rsvg because it's supposed to pull in it's own svg converter in the package libmagick?-extras where ? is the SONAME version, and is recommended by imagemagick.

However, as you can see in:
https://launchpadlibrarian.net/92231198/buildlog_ubuntu-precise-i386.librecad_1.0.0%2Bnolibs-1_FAILEDTOBUILD.txt.gz

it is pulling in:
libmagickcore4

but is NOT pulling in:
libmagickcore4-extra

since it is only a recommends.

So this is the real bug:
1) imagemagick's convert first will try to use the internal svg converter found in the recommended package libmagickcore4-extra. Since it is recommended, it is not pulled into the buildds.
2) When libmagickcore?-extra is missing on a system (such as the buildds and a user's system), "convert" will fall back to /usr/bin/rsvg. However, that file no longer exists in ubuntu.

The hack, for now, is to build depend on imagemagickcore4-extra - but that requires bumping the dependency name everytime libmagickcore gets a SONAME bump (which happened between oneiric and precise). or you can depend on libmagickcore-dev which will pull in the correct libmagickcore?-extra, but that's really overkill