Rebar3 Features (part 2): Dependency Tree

rebar3 tree is a new command to allow the user to view what dependency pulled in each transitive dependency. This is especially useful with rebar3’s dependency resolution strategy of “first wins”.

Thanks for pushing for this feature goes to Heinz N. Gies and inspiration comes from leiningen’s command lein deps :tree.

For an example I’ve cloned chef-server and built oc_erchef under src/oc_erchef. It is unique because it has both a top level app oc_erchef under src/ as well as additional project apps under apps/.

Additionally, I’ve added _checkouts/erlware_commons to show how checkout dependencies, an application linked to under _checkouts/, is moved to the top level and marked as (checkout app) and switched lager to a hex package dependency, the rest being git sourced dependencies.

$ rebar3 tree
├─ chef_db─12.1.2-6047c67 (project app)
├─ chef_index─12.1.2-6047c67 (project app)
├─ chef_objects─12.1.2-6047c67 (project app)
├─ chef_test─12.1.2-6047c67 (project app)
├─ depsolver─12.1.2-6047c67 (project app)
├─ erlware_commons─0.16.0 (checkout app)
├─ oc_chef_authz─12.1.2-6047c67 (project app)
├─ oc_chef_wm─12.1.2-6047c67 (project app)
└─ oc_erchef─12.1.2-6047c67 (project app)
   ├─ bcrypt─0.0.0+build.87.ref085eb59 (git repo)
   ├─ chef_authn─0.0.0+build.86.refe7850d0 (git repo)
   ├─ darklaunch─0.0.0+build.72.ref05881cb (git repo)
   │  └─ meck─0.8.3 (git repo)
   ├─ efast_xs─0.1.0 (git repo)
   ├─ ej─0.0.0+build.87.ref132a9a3 (git repo)
   ├─ envy─0.0.0+build.38.ref954c87a (git repo)
   ├─ eper─0.90.0 (git repo)
   ├─ folsom─0.0.0+build.335.ref38e2cce (git repo)
   │  └─ bear─0.0.0+build.32.ref1192345 (git repo)
   ├─ folsom_graphite─0.0.0+build.41.refd4ce9bf (git repo)
   ├─ gen_bunny─0.1 (git repo)
   │  ├─ amqp_client─0.0.0 (git repo)
   │  └─ rabbit_common─0.0.0 (git repo)
   │     └─ gen_server2─1.0.0 (git repo)
   ├─ ibrowse─4.0.1.1 (git repo)
   ├─ jiffy─0.0.0+build.131.reff661ee9 (git repo)
   ├─ lager─2.1.1 (hex package)
   │  └─ goldrush─0.1.6 (hex package)
   ├─ mini_s3─0.0.1 (git repo)
   ├─ mixer─0.1.1 (git repo)
   ├─ neotoma─0.0.0+build.125.ref760928e (git repo)
   ├─ opscoderl_folsom─0.0.1 (git repo)
   ├─ opscoderl_httpc─0.0.1 (git repo)
   ├─ opscoderl_wm─0.0.1 (git repo)
   │  └─ webmachine─0.0.0+build.526.ref7677c24 (git repo)
   │     └─ mochiweb─2.9.0 (git repo)
   ├─ pooler─0.0.0+build.159.ref7bb8ab8 (git repo)
   ├─ sqerl─1.0.0 (git repo)
   │  └─ epgsql─3.1.0 (git repo)
   ├─ stats_hero─0.0.0+build.73.refff00041 (git repo)
   │  └─ edown─0.2.4+build.66.ref30a9f78 (git repo)
   ├─ sync─0.1.3 (git repo)
   └─ uuid─1.3.2 (git repo)
      └─ quickrand─1.3.2 (git repo)