How do you update safely to 0.6 the working C-Lightning node?
You should be able to just stop the old version, download the new binaries, unpack them, and run them. On the first start
lightningd will take care of updating the database if necessary and
Alternatively you can also compile the binaries yourself, like you did before the release:
git clone https://github.com/ElementsProject/lightning.git /opt/lightning cd /opt/lightning ./configure --disable-developer --disable-valgrind make sudo make install
lightning-cli will be in your
$PATH and available from everywhere.