It's sick to start compiling kde again if i get a compiler error for example, when if i would be compiling it on my own i would just typed "make" and allow it to resume compiling. Because portage deletes the temp dirs when compiling is done (successful or not) we cant do this right now. I saw some parameter to disable this, but i am not too sure if this was intented for this behaviour
That parameter is FEATURES+="noclean" in make.conf. When set, the workdir won't be removed, either after a sucessful or a failed emerge. You can then manually correct the problem and run ebuild file.ebuild compile install qmerge, which should resume the building from where it left off for at least 95% of the ebuilds. And yes, this is (partly) what it's intended for. Does this solve your problem?
This would be a "workaround" for my problem, and may work, but wont fix this rfe. The main goal of this rfe should be for portage to get smart enough to not clean the workdir if compiling fails. I think this is not that hard to do, we make portage only remove the temp dir if the compile was successful (of course unless we have noclean defined) This would save _everyone_ lots of _time_ I had to recompile ~10 times some packages in order to finally get kde compiled because of internal compiling errors (which is known and not gentoo's fault)
*** Bug 8775 has been marked as a duplicate of this bug. ***
I think that portage could has a flag file created in temp directory like this: /var/tmp/portage/any_package/temp/inprogress and when it start, it verify if this file is created, and then if it is, portage do not delete everything and on a sucefull emerge (and if noclean is not setted) portage delete this file.
Continuing on a possible corrupt build is not desired. If you want to risk it use FEATURES="noauto"