if i run 2 parallel emerge of two packages one of them crashes if they come to compile the same package. probably this is not a bug but maybe emerge could use some sort of locking system so when it find a locked package it can just wait for the other session to end its compilation, and then continue with the other packages in list..
This is fixed in svn r3920.
This has been released in 2.1.1_pre3-r2.
*** Bug 78771 has been marked as a duplicate of this bug. ***
This is more properly fixed as of svn r4521. PORTAGE_BUILDDIR is locked throughout all of the phases now, so there's no chance that a parallel emerge process can interfere with it while another one is using it.
This has been released in 2.1.2_pre1-r2.