pbuilder, convert svg->png

[Felix Natter <fnatter@gmx.net>]

hi,

when setting up pbuilder on a sid VM as mentioned here:
  https://www.debian.org/doc/manuals/maint-guide/build.en.html#pbuilder
and then running [1]:
 $ gbp buildpackage -us -uc
followed by:
 $ BUILDER=pbuilder git-pbuilder 

Question 1: 
I learned these commands by heart. Is there a good tutorial/blog/... for
running any chroot (pbuilder, cowbuilder, sbuild...) from a git repo
(using git-buildpackage toolset), so that I understand this?

When the build calls:
  convert -background none -geometry !48x48 \
  freeplane_framework/script/freeplane.svg 48x48/freeplane.png

it fails most probably because librsvg2-bin is not installed (it
contains /usr/bin/rsvg-convert:
https://packages.debian.org/sid/amd64/librsvg2-bin/filelist):

---------------------
mkdir 48x48
convert -background none -geometry !48x48 freeplane_framework/script/freeplane.svg 48x48/freeplane.png
convert.im6: delegate failed `"rsvg-convert" -o "%o" "%i"' @ error/delegate.c/InvokeDelegate/1065.
convert.im6: unable to open image `/tmp/magick-EQZwa67o': No such file or directory @ error/blob.c/OpenBlob/2638.
convert.im6: unable to open file `/tmp/magick-EQZwa67o': No such file or directory @ error/constitute.c/ReadImage/583.
convert.im6: no images defined `48x48/freeplane.png' @ error/convert.c/ConvertImageCommand/3044.
make: *** [build] Error 1
---------------------

Question 2:

- why is librsvg2-bin not installed on sid?? They contain the same
  imagemagick version, and both have librsvg2-2 2.40.0-1 installed which
  "Suggest" librsvg2-bin
  => I guess the solution is to add librsvg2-bin to build-depends?

Question 3:
- why does a local build on sid ("gbp buildpackage -us -uc") work in
  this case? I guess my pbuilder setup is broken?

Many Thanks and Best Regards,
-- 
Felix Natter