when you build a defconfig with make something_defconfig and afterwards want to edit the linux kernel configuration (make linux26-menuconfig), then buildroot can't chdir in the output/build directory, because it is not yet created. some output (sorry error message is in german): bzcat /home/ich/buildroot-2010.02/dl/linux-2.6.32.9.tar.bz2 | tar -C /home/ich/buildroot-2010.02/output/build -xf - tar: /home/ich/buildroot-2010.02/output/build: Kann chdir nicht ausführen: Datei oder Verzeichnis nicht gefunden when you create the output/build folder by your own, it works.
this bug report also holds for buildroot-2010.02
I believe this was fixed by c9ff3273eb94: commit c9ff3273eb94078ad342d0a3e08e1757bced2afa Author: Peter Korsgaard <jacmet@sunsite.dk> Date: Tue Jul 20 08:45:45 2010 +0200 linux: linux26-{menu,x,g}config needs host-sed Similar to how it's done for uclibc-menuconfig. Reported-by: Paul Jones <paul@pauljones.id.au> Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk> It works here atleast. If not, please reopen the bug report with more info.