gnucash conflicts with guile?

[Bob Eager]

I have just tried to build gnucash, but it seems to have a conflict
with guile, of all things:

gmake[5]: Leaving directory '/usr/ports/lang/guile/work/guile-1.8.8'
gmake[4]: Leaving directory '/usr/ports/lang/guile/work/guile-1.8.8'
gmake[3]: Leaving directory '/usr/ports/lang/guile/work/guile-1.8.8'
gmake[2]: Leaving directory '/usr/ports/lang/guile/work/guile-1.8.8'
====> Compressing man pages (compress-man)
====> Running Q/A tests (stage-qa)
Error: /usr/local/lib/libguilereadline-v-17.so.17.0.3 is linked to /usr/local/lib/libreadline.so.6 from devel/readline but it is not declared as a dependency
Warning: you need USES+=readline
===>  Installing for guile-1.8.8_3
===>  Checking if guile already installed
===>   Registering installation for guile-1.8.8_3 as automatic
Installing guile-1.8.8_3...
pkg-static: guile-1.8.8_3 conflicts with guile2-2.0.14 (installs files into the same place).  Problematic file: /usr/local/bin/guile
*** Error code 70

Stop.
make[1]: stopped in /usr/ports/lang/guile
*** Error code 1

Stop.
make: stopped in /usr/ports/finance/gnucash


Does anyone else know about this, and any workaround?

-- 
Bob