# debtree — package dependency graphs on steroids

### Introduction ### Advanced usage examples Create a build dependency graph Visualize what would happen when installing a package Dependencies on virtual packages Reverse dependencies The top graph for `pident` incudes three dependencies on virtual packages and shows how virtual packages and the packages that provide them can be displayed. The first is a fairly common dependency on `debconf | debconf-2.0` where the latter is a virtual package provided by either `debconf` or `cdebconf`. `debconf` has square brackets because it is also included in the alternative dependencies; `cdebconf` has curly brackets because its dependencies are not included anywhere in the graph. The second is the virtual package `inet-superserver`. Because the maximum number of providers was set to 5 and there are 4 packages that actually provide this virtual package, all providing packages are shown. `openbsd-inetd` has square brackets because it was also displayed as the preferred alternative; for the others no dependencies are shown and thus their names have curly brackets. The third is the virtual package `ident-server`. There are 7 packages that provide this virtual package, which is more than the maximum that was set. Therefore no individual providing packages are shown, but the total number of providing packages is shown alongside the arrow for the relationship. Note that the requested package `pidentd` is one of the providing package. Adding the option `-I` (show installed packages) when generating this graph, could result in the bottom graph, which has the following changes: as `debconf` is installed, `debconf-2.0` is no longer shown and thus the providing packages are not shown either; the ellipsis in the second row indicates there are other packages that can satisfy the alternative dependency as `openbsd-inetd` is installed, only that providing package is shown as alternative and thus again `inet-superserver` and its providing packages are no longer included as `pidentd` is installed, only that providing package is shown for `ident-server`; as `ident-server` is provided by the requested package, this virtual package is still shown; the ellipsis in the second row indicates there are other (undisplayed) providing packages Note that for this second graph the option `--max-providers`is no longer relevant.`` |  | `$ debtree --max-providers=5 pident`
Generated .dot file: | DOT
Full-sized images: | PS | PNG | SVG
`$ debtree -I pident`
Generated .dot file: | DOT
Full-sized images: | PS | PNG | SVG