Find a wrong version in current directory #4

Sometime ago, I compiled 3.3.1. Ketchup downloaded and unpacked the tarball.

To identify successive compilation, I added a suffix:

$ grep LOCALVERSION .config
CONFIG_LOCALVERSION="-skc2"
CONFIG_LOCALVERSION_AUTO=y

Nothing was updated in the source files:

$ head -5 Makefile
VERSION = 3
PATCHLEVEL = 3
SUBLEVEL = 1
EXTRAVERSION =
NAME = Saber-toothed Squirrel

My 3.3.1-skc2 is running fine, but now I want to update to 3.3.5.

$ make clean
...
$ ketchup 3.3.5
3.3.1-skc2 -> 3.3.5
ketchup: Unknown tree/patchset!

Ketchup think I'm using an unknown tree :(