Sorry for the late response. Please try to build blockdiag with libmagickcore-6.q16-3-extra package. This extra lib has the SVG codec.
- Bug#860689: blockdiag: FTBFS on i386: E: Build ... Lucas Nussbaum
- Bug#860689: blockdiag: FTBFS on i386: E: B... Christian Hofstaedtler
- Bug#860689: blockdiag: FTBFS on i386: ... Changwoo Ryu
- Bug#860689: blockdiag: FTBFS on i3... Changwoo Ryu
- Processed: Re: Bug#860689: blo... Debian Bug Tracking System
- Processed: Re: Bug#860689: blockdiag: FTBF... Debian Bug Tracking System
- Bug#860689: marked as done (Missing Build-... Debian Bug Tracking System