In the mentioned version, parallel-fetch doesn't work. emerge foo says: Starting parallel fetching, but it doesn't. It downloads every file as "parallel-fetch" would be disabled.
*** Bug 137107 has been marked as a duplicate of this bug. ***
Created attachment 89416 [details, diff] log parallel-fetch output to /var/log/emerge-fetch.log I'm able to reproduce the problem here. It's due to doebuild getting confused by the category (related to some changes I made recently). I'm working on a patch to fix it now.
Created attachment 89420 [details, diff] make sure doebuild gets the correct CATEGORY This is fixed in svn r3524.
This has been released in 2.1.1_pre1-r1.