Thanks for your hint, I tried it. I get this message on installing libdb4.8. I believe, the description for compiling the xsh sources is very old. I will not try until there are current ones.
# apt-get install libdb4.8-dev libdb4.8++-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package libdb4.8++-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
If you renew the sources, it seems appropriate to make an installion for a current 18.04.1 ubuntu.