Dune: list all dependencies, grouped by license

Learning
1

Is there a way to tell dune to list all the dependencies of the current project, grouped by license ?

Thanks!

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2

opam is the responsable of the project dependencies.

opam list

But there’s no way that I know of listing the licenses with list.

3

I think the following might work (e.g. with eio). The package will have to be pinned if it isn’t released I think.

opam list --required-by=eio --recursive --column=name,license:
2 Likes
4

Unless one is using per-project-switch, I believe opam list is all installed pkgs, not merely what current dune build needs.

Furthermore, I believe opam list also includes ocaml, even if dune build never pulls in the ocaml sources as a dep.

5

I don’t think there’s anything off-the-shelf that does specifically what you want, but there are some packages which can collect dependencies of a project at least.

dune-deps | grep ' ->' | sed 's/"lib:\([^"]*\)"/\1/g' | sed 's/.*->//' | sort | uniq
6

Very nice. For future reference, I’ll note that we can specify the version of the package so as to get only the dependencies for the selected version. For example, yojson 2 dropped the dependency on biniou and this can be seen by specifying yojson.2.0.2 instead of just yojson:

$ opam list --required-by=yojson.2.0.2 --recursive --column=name,license:
# Packages matching: (installed | available) & rec-required-by(yojson.2.0.2)
# Name                   # License
base-bytes
base-num
base-ocamlbuild
base-threads
base-unix
conf-m4                  "GPL-3.0-only"
cppo                     "BSD-3-Clause"
dkml-base-compiler       "Apache-2.0"
dkml-runtime-common      "Apache-2.0"
dune                     "MIT"
jbuilder                 "MIT"
num                      "LGPL-2.1-only WITH OCaml-LGPL-linking-exception"
ocaml                    "LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception"
ocaml-base-compiler      "LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception"
ocaml-config
ocaml-option-nnp
ocaml-secondary-compiler "LGPL-2.1-only WITH OCaml-LGPL-linking-exception"
ocaml-variants           "LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception"
ocamlbuild               "LGPL-2.0-or-later WITH OCaml-LGPL-linking-exception"
ocamlfind                "MIT"
ocamlfind-secondary      "MIT"
seq
yojson                   "BSD-3-Clause"

To group by license, | sort -k2 does the job.

Regarding the original question:

What worked for me in the past is to use a clean opam switch that contains only the packages needed by the current project. opam list without specifying a specific package will produce the desired list. Here is the command:

$ opam list --column=name,license: | grep -v '^#' | sort -k2

I don’t know how to turn a list of opam files specifying dependencies into an opam list ... command with the correct filters. I would love to know as well.

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7

If you have that you can also use various commands of odig to access the actual license files

odig show license -l        # License tags of installed packages 
odig show license-files -l  # Path to license files 
odig license --no-pager     # All licenses separated by U+001C

Of course this can be combined with opam for example:

odig license --no-pager $(opam list --required-by=$PKG -s)

but one should be careful with --required-by/--depends-on, see this issue.

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8

opam list permit to list dependencies (and related information) of a (or several) package, it don’t need to be installed. The default search is installed | available. For a local project, you need to pin it (without installing) to make opam aware of the package.

opam pin . --no-action

If you specified project dependencies in dune-project, dune should have generated an up-to-date opam file locally.
Once pinned, you can use opam list with that package, as with any other package

opam list --required mypkg --recursive --column=name,license:

If you need to constraint to only installed ones, you can use option --installed. All options are available in the man page.

If you use --short, you don’t need to grep output.

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