Pinta doesn't allow me to select any tool other than lasso selection

[Pete]

Expected behavior: Upon clicking on a tool that tool will become selected and allow me to work with it.
Actual behavior: The selection jumps back to lasso and the lasso tool also is active and usable.

> pinta --version
1.6

> lsb_release -rd
Description: Ubuntu 18.04.1 LTS
Release: 18.04

> apt-cache policy pinta
pinta:
  Installed: 1.6-2
  Candidate: 1.6-2
  Version table:
 *** 1.6-2 500
        500 http://archive.ubuntu.com/ubuntu bionic/universe amd64 Packages
        500 http://archive.ubuntu.com/ubuntu bionic/universe i386 Packages
        100 /var/lib/dpkg/status