Platform Team/Guide/Sweets Usage

This guide describes how to use Sugar Labs' Packaging Management System. See also introduction page and Packaging guide.

Installation

Required packages

First, install PackageKit related packages. The following command will install two Polkit authentication agents, one for Gnome session (if you start sugar emulator from Gnome Desktop Environment) and LXPolkit, which will be used from Sugar session.

Fedora specific instructions:

sudo yum install gnome-packagekit lxpolkit

Debian and Ubuntu specific instructons (there is no official package for LXPolkit?):

sudo apt-get install packagekit-gnome

Relogin from X session to let Gnome or Sugar start the Polkit authentication agent.

Install

wget http://download.sugarlabs.org/sweets/sweets/installer.sh
sh installer.sh

Relogin from X session to take into account the new PATH environment variable value.

Besides, sweets might be run from the sources.

Upgrade

If sweets was installed from a bundle:

sweets upgrade

Usage

Read the Sweets Glossary to understand the basic concept (and overview of the bigger picture). The rest of the text will operate with the following terms:

• SWEET, the full interface URL, like http://sweets.sugarlabs.org/sdk/sugar, or the short one, like sdk/sugar;
• COMMAND, sweet's command that indicates how to run a particular sweet; by default, sweets have only the run command, but it is possible to have several commands;
• VERSION, sweet's version

See the Sugar via Sweets section for real examples of how to use Sweets to run Sugar Shell.

Launch

To launch a sweet with verbatim passing of optional ARGUMENTS:

sweets SWEET [ARGUMENTS]

Sometimes sweets support several launching commands; it is possible to specify one during the launch:

sweets SWEET:COMMAND

To run a particular, but not the latest, version:

sweets SWEET =|>=|<= VERSION

To get the full list of available versions:

sweets status SWEET -v

To get information, e.g., a list of supported commands, about a sweet:

sweets show SWEET

Troubleshooting

Feeds are being updated from time to time. After experiencing any problems, and for refreshing the local feeds cache, it will be useful to re-download feeds. Use, once, the -R command line argument for the launch command (make sure that -R goes before the SWEET, because using it afterwards will cause passing it as a SWEET's argument):

sweets -R SWEET

If sweets can't find a proper implementation, see the e lines in the output of:

sweets status SWEET -vdd

Search

It is possible to search sweets among locally known ones and those registered on http://sweets.sugarlabs.org (not yet implemented). The search is based on the Xapian search engine. Thus, it is possible to use Xapian's query language.

For command format is:

sweets search QUERY

Notice that partial search is enabled. So, the query tele will be treated as tele* to search all words that start from tele.

sweets supports the following search prefixes based on recipe options:

• interface the first interface from the implementations list, e.g., http://sweets.sugarlabs.org/sdk/sugar;
• sweet the first interface from the implementations list in short Sweets notations, e.g., sdk/sugar;
• implement the list of implemented interfaces;
• associate the list of associated interfaces;
• name the short name of a sweet;
• summary sweet's summary;
• description long sweet's description;
• category list of category names;
• license list of licenses;
• type sweet's type, which might be library, application or activity;
• keep if activity, that a sweet is representing, is favorited;
• tags the list of sweet's tags;
• mime_types the list of activity MIME types, that a sweet is representing or supports.

So, it is possible to search only among particular sweet attributes, like name:telepathy to search only among particular sweet names.

sweets support additional notation for exact searching in the form of prefix:=string. For example the query name:=sugar will find sweets only with exactly sugar as a name and omit names like sugar-base. If the search string contains spaces, wrap it within double quotes, name:="Sugar Commander". Note, wildcards do not work in the exact search case where asterisks will be treated literally.

Sugar via Sweets

To try Sweets in practice, run several Sugar versions. On the Sweets level, there are not any restrictions to using Sweets on any GNU/Linux distribution. Successful usage depends only on the presence of PackageKit and the quality of the sweet packages (sweets). For now, sugar sweets are well aware of Fedora, Debian/Ubuntu, and Gentoo package names and not so well aware of openSUSE and Mandriva. Sugar sweets launchs were tested on some recent Fedora and Ubuntu releases. The quality of other GNU/Linux distribution support depends only on how often Sweets is used on these distributions and the reporting of problems by the community.

Note, Sugar Shell does not start the authentication agent, and preparing sugar to start can be processed only in a Desktop Environment, e.g., Gnome (or launch authentication agent manually).

There are two sweets for Glucose:

• sdk/sugar, for pristine Glucose;
• dextrose/sugar, for Glucose with Dextrose patches applied.

To see what Glucose versions these sweets provide, type in a terminal:

 sweets status sdk/sugar -v

To launch a recent stable Sugar version in emulator mode, type in a terminal:

sweets sdk/sugar:emulator

By default, the most recent stable version will be used. To run a particular version, execute with additional arguments:

sweets sdk/sugar:emulator = 0.88

For now, since there is no Sweets support in the Shell to run activities as sweets, Glucose sweets contain Fructose and Sugar Platform dependencies. To run Sugar Shell without them, use the shell command:

sweets sdk/sugar:shell

If you need to develop Sugar, see Sweets Packaging guide's instructions.

Sugar sweet from X sessions

To start Sugar in the session mode, i.e., not from Xephyr, it will be useful to add a new X session. Place sweets invocation into your ~/.xsession file:

PATH=$HOME/.local/bin:$PATH
sweets sdk/sugar

and create a /usr/share/xsessions/sweets.desktop desktop file:

[Desktop Entry]
Encoding=UTF-8
Name=Sweets
GenericName=Sweets
Exec=/etc/X11/Xsession
Type=Application

After getting a login screen, Sweets session should be present in the sessions list.

Current limitations

• For now, sweets knows only enough about the glucose dependencies to install them from native packages in Debian, Ubuntu, Fedora, Mandriva, openSUSE, and Gentoo.
• Activities can't reuse sweets benefits.

Feedback

• Submit your bug report or feature request.
• Subscribe to the sugar-devel mailing list and email with the subject prefixed with [SWEETS].
• Ask your question on IRC channels, #sugar (not logged) or #sugar-newbies (logged).