Title:Portage handling of ACCEPT_LICENSE
Last-Modified:2004/10/26 00:21:28
Author:Jason Stubbs <jstubbs at>, Marius Mauch <genone at>
Type:Standards Track
Post-History:8-Mar-2004 10-Mar-2004 25-Oct-2004 18-Nov-2006



Currently, every ebuild in the portage tree 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.


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.


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:


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:

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

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, portage 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-INTERACTIVE. NON-INTERACTIVE licenses are those that don't require interactive 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). The format of this file is

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

Also any line starting with # is ignored and may be used for comments. License groups may not contain negated elements, so a group

mygroup foo -bar -bla

is illegal.


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:


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

Portage Behaviour

Unaccepted licenses will be treated like any other masked package, that is emerge 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.


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-INTERACTIVE in the main gentoo repository as there will be no internal default in portage.


[1]Gentoo Linux Bug 17367 (
[2]Gentoo Linux Bug 34146 (


This document has been placed in the public domain.