l3packages (http://ctan.org/pkg/l3packages) and others are available online, but g-ctan-2011.1 does not know how to handle them:
# g-ctan -l | grep l3
# g-ctan -e l3packages
* l3packages is not known to me. Either get a new package database or correct the package name. This error can happen for valid package names if there has been no update since the current TeXLive version.
The new l3kernel and other l3* replace expl3, thus upgrading only l3kernel alone breaks some l3 features (notably xparse).
How is one supposed to install those dependencies? Moreover, direct use of tlmgr cannot be used directly with gentoo, thus it's *very* easy to get stuck :-(
Steps to Reproduce:
1. install+configure g-ctan
2. try to install a non-listed (not reported by "g-ctan -l") package
There should be a way to inject new package information for packages not listed by "g-ctan -l"
Same things happening to me with e.g. todonotes. Package is listed in /var/cache/g-ctan/texlive.tlpdb.
The error text "This error can happen for valid package names if there has been no update since the current TeXLive version" appears to be the key, but I don't really understand what it means.
In the meantime, I found a workaround for installing listed packages. Instead of using '-e' to build and emerge a package, I split the process like this:
[$ g-ctan -a]
$ g-ctan -c l3packages
$ emerge l3packages
That worked fine for me (and maybe it's the correct way!), apart from the fact the "texdoc" keeps finding docs of old system packages instead of the new ones...
The package has been removed.