This page details the work being done to port GNU libc to OpenSolaris. NPTL (libpthread) has also been ported and extended to work with OpenSolaris. Additional, some OpenSolaris extensions have also been implemented. The unofficial name of the port is GNU/kOpenSolaris.
You will also need to create an 'arch=all' mirror. This can be done with the following command:
debmirror --nosource -p -v -h ftp.nl.debian.org -r debian --method=http -d \ sid -s main /var/www/solaris2/all --arch amd64 --exclude "_amd64.deb$"