I cant find a way around this. In my case it is gnochm that pulls the offending packages and by removing that everything is fine. But I cannot merge it and I can't resolv the following blocker:
[ebuild N ] dev-libs/chmlib-0.39-r1 0 kB
[ebuild N ] dev-python/pychm-0.8.4 0 kB
[ebuild N ] dev-python/libgksu-python-2.19.1 USE="-debug -examples" 0 kB
[ebuild N ] dev-python/gtkspell-python-2.19.1 USE="-debug -doc -examples" 0 kB
[ebuild N ] dev-python/egg-python-2.19.1 USE="-debug -examples" 0 kB
[ebuild NS ] gnome-extra/libgda-3.0.4 [1.2.4] USE="berkdb ldap mysql -bindist -debug -doc (-firebird) -freetds -oci8 -odbc -postgres -xbase" 0 kB
[ebuild N ] dev-libs/gdl-2.24.0 USE="-debug -doc" 0 kB
[ebuild NS ] gnome-extra/gtkhtml-2.11.1 [3.24.5] USE="-accessibility -debug -test" 0 kB
[ebuild N ] dev-python/gtkhtml-python-2.19.1 USE="-debug -examples" 0 kB
[ebuild N ] dev-python/gdl-python-2.19.1 USE="-debug -examples" 0 kB
[ebuild N ] dev-python/libgda-python-2.19.1 USE="-debug" 0 kB
[ebuild N ] dev-python/gnome-python-extras-2.19.1-r3 0 kB
[ebuild N ] app-text/gnochm-0.9.11 USE="-debug" 0 kB
[blocks B ] <dev-python/gdl-python-2.19.1-r1 ("<dev-python/gdl-python-2.19.1-r1" is blocking dev-libs/gdl-2.24.0)
Total: 13 packages (11 new, 2 in new slots), Size of downloads: 0 kB
Conflict: 1 block (1 unsatisfied)
* Error: The above package list contains packages which cannot be
* installed at the same time on the same system.
('ebuild', '/', 'dev-python/gdl-python-2.19.1', 'merge') pulled in by
=dev-python/gdl-python-2.19.1* required by ('ebuild', '/', 'dev-python/gnome-python-extras-2.19.1-r3', 'merge')
Edit:
Found this
http://bugs.gentoo.org/show_bug.cgi?id=268359
Stabilizing dev-python/gdl-python-2.19.1-r1 is what is missing