Arch Linux

Description:

pacman is licensed under GPL, but must be linked with OpenSSL to use --with-openssl as is the current default.
Unfortunately, the GPL and the OpenSSL license are incompatible [1][2].

There are two possible solutions to solve this problem:
- your software must be rewritten to use a crypto library besides OpenSSL,
- or, your license must add an exception to the GPL which allows
linking with OpenSSL.

To add a license exception:

1. Add the attached LICENSE file to your code (COPYING in the case of pacman). This file tells that your
code is GPL, with an exception which allows linking with OpenSSL. Here
is the text of the exception:

***
In addition, as a special exception, the copyright holders give
permission to link the code of portions of this program with the
OpenSSL library under certain conditions as described in each
individual source file, and distribute linked combinations
including the two.
You must obey the GNU General Public License in all respects
for all of the code used other than OpenSSL. If you modify
file(s) with this exception, you may extend this exception to your
version of the file(s), but you are not obligated to do so. If you
do not wish to do so, delete this exception statement from your
version. If you delete this exception statement from all source
files in the program, then also delete it here.
***

2. Add the LICENSE.OpenSSL to your source code: https://www.openssl.org/source/license.txt


[1] http://www.gnu.org/philosophy/license-list.html
[2] https://people.gnome.org/~markmc/openssl-and-the-gpl.html