[systemd-devel] `Found ordering cycle on _SERVICE_` loops due to `local-fs.target` with `Requires` instead of `Wants` for mounts generated from `/etc/fstab`

[Michal Sekletar]

On Wed, May 9, 2018 at 9:42 PM, Uoti Urpala <uoti.urpala at pp1.inet.fi> wrote:

> What information would the graph contain? The basic structure of a
> cycle is always just a simple ring, and I don't see what benefit making
> a graph of that would give over just listing the nodes in order.

The simple transformation of the current text output to graph form is
not very helpful, but I think we could provide more than that. For
example, highlighting a job that systemd removed to break the cycle,
annotating edges with dependency origin (e.g. implicit dependencies
colour-coded differently), highlighting anchor job of the transaction
if it is present in the cycle.

Basically, I am trying to figure out what relevant pieces of the
runtime state could be captured in such graph and help admins (or
maintainers) to understand and fix the dependency cycle in their
environment.

Michal