When I replaced the python link to python3.4 quite a while ago in fresh
Devuan, aptitude or apt-get started complaining errors. So I installed
python2.7 and the errors gone.

lrwxrwxrwx 1 root root    9 Jul  2 21:18 python -> python2.7
lrwxrwxrwx 1 root root    9 Mar 17  2015 python2 -> python2.7
-rwxr-xr-x 1 root root 3.7M Mar  1  2015 python2.7
lrwxrwxrwx 1 root root    9 Dec  1  2014 python3 -> python3.4
-rwxr-xr-x 2 root root 4.3M Oct  8  2014 python3.4

But I use Python 3 when I write codes. I put python version at the first
line of code like below.

# Python 3.4
# domeutil.py