[Android Software/Hacking General [Developers Only]] onliner:
Hi, I'm having some problems trying to build different kernels.

onliner@randomPC:~/kernel_test$ make clean
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
/bin/sh: 1: cannot create fs/.cache.mk: Permission denied
security/Kconfig:393:warning: defaults for choice values not supported
security/Kconfig:397:warning: defaults for choice values not supported
security/Kconfig:401:warning: defaults for choice values not supported
security/Kconfig:405:warning: defaults for choice values not supported
security/Kconfig:409:warning: defaults for choice values not supported
.config:9487:warning: symbol value 'm' invalid for KVM
make[4]: *** [silentoldconfig] Error 1
make[3]: *** [silentoldconfig] Error 2

The strange thing is: this problem seems to be random because sometimes I can build kernels without problems, it's probably something on my PC, but I don't know what the problem is.