schroot mounting directory from host

[jffry@posteo.net]

Hi schroot maintainers!

I'm trying to debug a change in imagemagick which is causing gscan2pdf 
tests to fails, thereby preventing imagemagick 8:6.9.11.57+dfsg-1 from 
migrating to testing:

https://qa.debian.org/excuses.php?package=imagemagick

Up to now, I have just been using schroot via sbuild to build gscan2pdf 
in a clean chroot before uploading. I've also seen that I can launch 
schroot interactively, but that (understandably by default) seems to 
have no access to the host, but it would be much more comfortable to 
mount the host directory where I am debugging the package so that I can 
see the directory in both the the chroot and the host.

How can I achieve this on a case by case basis?

Thanks and regards

Jeff Ratcliffe