mubench update fails in dev environment

[salsolatragus]

Currently, ./mubench update fails with the following error:

fatal: cannot run ssh: No such file or directory
fatal: unable to fork

This is from running git pull in the Docker environment. Seems like we're missing some dependency?

Update: I realized this only happens in my/the dev environment, when the project is cloned via ssh. On the fresh clone following our setup guide (which uses https) everything works fine.