[wojciechpolak]

Because: "Fossil, in contrast, puts more emphasis on recording exactly what happened, including all of the messy errors..."

[mpweiher]

Logical errors, dead-ends.

You don't commit when the tests fail.

[Cthulhu_]

Shouldn't, and shouldn't be able to (git pre-commit hook), but some people don't have that, some people use git as cmd+s.