GLEP:23
Title:Handling of ACCEPT_LICENSE
Version:1.5
Last-Modified:2006/11/19 22:46:27
Author:Jason Stubbs <jstubbs at gentoo.org>, Marius Mauch <genone at gentoo.org>
Status:Accepted
Type:Standards Track
Content-Type:text/x-rst
Created:9-Mar-2004
Post-History:8-Mar-2004 10-Mar-2004 25-Oct-2004 18-Nov-2006 19-Nov-2006

Contents

Abstract

Currently, every ebuild in the main gentoo repository is required to have a valid LICENSE entry. However, the syntax of this entry is not officially defined and the entry itself is only used when outputting package details.

Status Update

Repoman has been updated to check for the LICENSE syntax. A development portage branch with support for ACCEPT_LICENSE and license groups exists.

Motivation

Many users wish to regulate the software they install with regards to licenses for various reasons [1]. Some want a system free of any software that is not OSI-approved; others are simply curious as to what licenses they are implicitly accepting.

Furthermore, some software requires that a user interactively accept its license for its author's to consider it legally binding. This is currently implemented using eutils.eclass.

Specification

Ebuild LICENSE Variable

Most ebuilds are for software which is released under a single license. In these cases, the current LICENSE variable can remain as is. For example:

LICENSE="single-license"

However, there are several ebuilds for software which is released under several licenses, of which the user must accept one, some or all [2]. To complicate this, some ebuilds include optional components which fall under a different license.

To accomodate these cases, LICENSE syntax should accomodate all functionality offered by a DEPEND string. To keep things simple, this GLEP proposes that the syntax be identical. For example:

LICENSE="mandatory-license
    || ( choosable-licence1 chooseable-license-2 )
    useflag? ( optional-component-license )"

License names may contain [a-zA-Z0-9] (english alphanumeric characters), _ (underscore), - (dash), . (dot) and + (plus sign).

License Groups

Almost all users are willing to install any software that is FSF-approved. Other users are willing to install any software and implicitly accept its license. To this end, implementations will also need to handle grouping of licenses.

At a minimum, there needs to be the groups GPL-COMPATIBLE, FSF-APPROVED, OSI-APPROVED and NON-MUST-HAVE-READ. NON-MUST-HAVE-READ licenses are those that don't require manual acceptance for to be considered legally binding. This is the current behaviour of portage.

These groups are defined in a new file license_groups in the profiles subdirectory of the tree (or overlays). Details of handling groups defined in overlays is implementation dependent.

The format of this file is

<groupname> <license1> <license2> ... <licenseN>

Also any line starting with # is ignored and may be used for comments. Group names use the same syntax as normal license names. Also license groups may contain other groups. License groups may not contain negated elements, so a group

mygroup foo -bar -bla

is illegal.

ACCEPT_LICENSE

This GLEP proposes that a user be able to explicitly accept or decline licenses by editing a new variable ACCEPT_LICENSE in /etc/make.conf. Again, to keep things simple, the syntax should be similar to that of other incrementals. For example:

ACCEPT_LICENSE="-* accepted-license -declined-license"

As an extension, ACCEPT_LICENSE must also support license groups. This GLEP proposes that the license group be prepended by the special character "@". For example:

ACCEPT_LICENSE="-* @FSF-APPROVED"

License groups may be negated with the result that all elements of that group are also negated.

Portage will also offer a package.license facility to offer this functionality on a per-package base (analog to package.keywords), other implementations may implement such a facility differently or not at all.

Behaviour

Unaccepted licenses will be treated like any other masked package, that is the user interface of an implementation will display a message listing any license that has to be accepted before the package can be merged with a pointer to the exact license text.

Past versions of this document proposed to handle license-masked packages like blockers, but this would be inconsistent with other visibility filters as well as the current blocker system (as a blocker affects two packages) and be more complicated to implement.

Rationale

An implementation of this proposal should make it easy for users wishing to regulate their software without affecting those that don't.

Reference Implementation

Available in portage svn repository under main/branches/license-masking

Backwards Compatibility

There should be no change to the user experience without the user explicitly choosing to do so. This mandates that the configuration variable be named ACCEPT_LICENSE as some users may already have it set due to ebuilds using eutil.eclass's implementation. It also mandates that the default ACCEPT_LICENSE be set to @NON-MUST-HAVE-READ in the main gentoo repository as implementations are not required to provide an internal default.

References

[1]Gentoo Linux Bug 17367 (http://bugs.gentoo.org/show_bug.cgi?id=17367)
[2]Gentoo Linux Bug 34146 (http://bugs.gentoo.org/show_bug.cgi?id=34146)

Copyright

This document has been placed in the public domain.