I'm pretty sure this is an internal thing ( emerge builds a depgraph with the current system, not the system that would be present at the time that package foo gets built. Fex. livecd log # emerge -p syslog-ng vixie-cron screen postfix These are the packages that I would merge, in order: Calculating dependencies ...done! [blocks B ] mail-mta/ssmtp (is blocking mail-mta/postfix-2.1.5-r2) [ebuild N ] dev-libs/libol-0.3.14 [ebuild N ] app-admin/syslog-ng-1.6.5-r2 [ebuild N ] net-mail/mailbase-0.00-r8 [ebuild N ] mail-mta/ssmtp-2.61 [ebuild N ] sys-process/vixie-cron-4.1-r4 [ebuild N ] app-misc/screen-4.0.2-r1 [ebuild N ] dev-libs/libpcre-5.0 [ebuild N ] dev-db/mysql-4.0.24 [ebuild N ] mail-mta/postfix-2.1.5-r2 [ebuild N ] dev-perl/Net-Daemon-0.37 [ebuild N ] dev-perl/Storable-2.13 [ebuild N ] dev-perl/PlRPC-0.2016-r1 [ebuild N ] dev-perl/DBI-1.38-r1 [ebuild N ] dev-perl/DBD-mysql-2.1027 livecd log # vixie-cron depends on virtual/mta. Postfix provides virtual/mta. However, postfix is not considered for the provide because it's after vixie-cron in the list of packages, when in fact it very well could be. livecd log # emerge -p syslog-ng postfix vixie-cron screen These are the packages that I would merge, in order: Calculating dependencies ...done! [ebuild N ] dev-libs/libol-0.3.14 [ebuild N ] app-admin/syslog-ng-1.6.5-r2 [ebuild N ] net-mail/mailbase-0.00-r8 [ebuild N ] dev-libs/libpcre-5.0 [ebuild N ] dev-db/mysql-4.0.24 [ebuild N ] mail-mta/postfix-2.1.5-r2 [ebuild N ] dev-perl/Net-Daemon-0.37 [ebuild N ] dev-perl/Storable-2.13 [ebuild N ] dev-perl/PlRPC-0.2016-r1 [ebuild N ] dev-perl/DBI-1.38-r1 [ebuild N ] dev-perl/DBD-mysql-2.1027 [ebuild N ] sys-process/vixie-cron-4.1-r4 [ebuild N ] app-misc/screen-4.0.2-r1 livecd log # moving postfix before vixie-cron fixes things, because portage assumes previously specified packages will install correctly. I talked to Jstubbs about this, and I figured I'd file a bug on it to make sure it gets in the new happy version of the dep-resolver and things. Also it should give a reference to anyone else looking for the same type of deal.
*** This bug has been marked as a duplicate of 1343 ***