I’ve been getting similar errors in various circumstances in the last 2 weeks or so. In my case it was with build stages using cmake, for snaps that had previously been building without issue.
In my case it was only showing up in cleanbuild runs, but today (on my Ubuntu 16.04 system) it started showing up with regular snapcraft calls, using apt-installed snapcraft (so, 2.43.1).
I’ve previously experienced it with snapcraft 3.1 and 3.1.1 snaps running inside LXD containers:
Note, in that report I note a -11 exit status, but I’ve also experienced 139, depending on what part is being built.