Fossil and Git are two great softwares, and I use them day by day.
Unluckily the former has less support by integrated environment, IDE, and this makes a little easier to deal with Git when working with mainstream development frameworks. But luckily, Fossil has a way to export to Git and, much more itneresting, to do a bidirectional import/export that is to export and re-import a git repository. In other words, you can work on a repository with both git and fossil pretty much at the same time.

Today I decided to realign my fossil repo to a git one, so to have the same logs and timeline available both from command like (i.e., fossil) and IDE tools. But I messed up everything:

fossil export 
 --export-marks /sviluppo/fossil/luca.fossil.marks 
  | git fast-import 

Who catch the error?
Well, the git mark points to the fossil repository file, not the mark file!
A whole repository destroyed in a few seconds.

The only thing that can save in such a situation is a backup, but, shame on me, I didn't have a fully recent one, so I lost part of the history.
Lesson learned: always do a backup before acting on a repository, even if you are supposed to only read from it (as in an export phase).
Lesson learned: do not trust the shell to complete paths and filenames for you.

The article How to destroy my fossil repository in one step! has been posted by Luca Ferrari on February 8, 2017