packages that depend the kernel should NOT be searching for "/usr/src/linux" the proper way is to use in /lib/modules/`uname -r`/build/ This way the legacy symlink of "/usr/src/linux" isn't needed.. packages that do this are alsa-driver, nvidia-kernel, comedi, aside from others (xfree-drm adn gatos-drivers may do this as well, but I have NOT verified) Reproducible: Always Steps to Reproduce: 1. delete /usr/src/linux (or if it's pointing to the NON-running kernel 2. emereg {alsa-driver,comedi,nvidia-kernel} 3. Actual Results: build dies due to /usr/src/linux symlink missing and/or incorrect Expected Results: the ebuild SHOULD NOT depend or even LOOK FOR /usr/src/linux. IT should ALWAYS use /lib/modules/`uname -r/build, which is guarranteed to be pointing to the right kernel source for the running kernel. not applicable...
read the gentoo-dev mail archives and bugzilla to see why we enforce /usr/src/linux and wont change that behavior