Google Summer of Code 2009

This is the main tracking page for MacPorts' Google ​Summer of Code.

Informations about the past years can be found at SummerOfCodeArchive.

Applications for SoC

Please note that the following informations are preliminary as acceptance for Google Summer Of Code 2009 is still pending.

General Info

Applications must be done online, on the ​Google SoC website. You will find more information on their page on ​Student Applications. Student applications must be submitted by April 3, 19:00 UTC. The official ​timeline should be consulted for the other dates.

There are several things to consider. We are willing to support and mentor students who want to gain an experience by working on The MacPorts Project. We have many ideas for potential internship subjects, yet we are open to anything that is both interesting and relevant to MacPorts. Motivated students do not necessarily need to know Tcl language beforehand, especially if they already know several script languages such as Python, Ruby, PHP or Perl.

For the MacPorts project

The best way to apply is to first make contact with us, either by sending a mail to the MacPorts developer ​mailing list, to the potential mentors listed below, or to IRC members on #macports on ​FreeNode.

What we expect from students for their applications:

• Write your own abstract and proposal, copying text from this idea page is not enough
• Get familiar with the MacPorts project resources. Especially check out the code and ​read the guide.
• Read the ​Tcl Tutorial
• Get in contact! Discuss your contribution ideas with potential mentors by e-mail, on the MacPorts development list or the IRC channel before applying.

Mentors

The following committers have agreed to be mentors for SoC 2009 (append @macports.org for e-mail)

Name	Area	Email
George Armah	GUI, Framework	armahg
James Berry	MPWA	jberry
Bryan Blackburn	Logging, self-management, general	blb
Jeremy Lavergne	Helping hand	snc
Perry Lee?	Co-mentoring	perry
Rainer Mueller	Administrator, config files, rev-upgrade, general	raimue

Tasks

This is a list of some potential tasks that student SoC members could undertake. These are just ideas, and while they express our current concerns, we are open to blue-sky projects related to MacPorts.

Please note that this list is absolutely not exclusive! If you have any idea about what you want to see improved in MacPorts, you are free to propose this as your own project. In any case, we recommend to talk to mentors before writing your application.

Core Tasks

Dependencies

This task consists of implementing a new dependencies engine for MacPorts. The current dependency engine properly deals with installing packages, but it does not deal satisfactorily with dependencies on variants (and versions), uninstalling and upgrading. This very challenging task requires a complete formalization of the use cases (installation, upgrade, uninstallation) and of the user needs before any implementation, as well as a deep understanding of the dependency relations (required for fetching, building, configuring; static and dynamic linking; dependence at runtime).

Classification: very challenging task
Programming languages: Tcl and C
Potential mentors: TBD

Logging

Currently MacPorts has no notion of logging of build activities of a given port or sets of ports. When a a build is attempted but an error keeps it from completing, there's no way to track the problem other than the build progress that was output to the terminal, if verbose mode was requested in the first place. Otherwise, the build environment has to be pruned and the build attempted once again to even get a look at the precise error message. This is particularly problematic when automated builds are attempted, since there's usually no one around to have a look at the failure spew. An infrastructure to remedy this situation and endow MacPorts with a rich set of logging capabilities has to be developed to open up the door to true automated build runs of large sets of ports and thus to packaging of binaries, since with logging we'd have a fully reliable way of catching, reporting and processing of all sorts of fetch/configure/build/destroot/install/etc errors.

This could be extended with the interaction with a server side application like MPWA that could consume these logs (read MPWA proposal). A more detailed draft of this task can be found on the LoggingProposal page.

Classification: medium task to relatively challenging
Programming languages: Tcl and C
Potential mentor: blb

Configuration files handling

MacPorts has no way to track configuration files. Currently if a configuration file is part of a port it will get overwritten on every upgrade which makes it less useful. At the moment, many ports only install default configuration files and the user has to copy it to the original location. But this always requires manual action and the user is not informed of updates in this configuration file.

For this task, investigate how other package management systems handle this. Find the best way to support it in MacPorts and implement it.

Classification: easy to medium task
Programming languages: Tcl
Potential mentor: raimue

Scan for broken dynamic libraries for rebuild

Upgrading any port can naturally break its dependents if using dynamic libraries. The only way to fix this is currently rebuilding all dependents, no matter if necessary or not. MacPorts should get a new command to scan installed dynamic libraries and binaries for linker errors and mark the corresponding port for rebuild. After checking all files, broken ones should get rebuild in the correct order. Probably it has to do the check again after each set of rebuilds.

port rev-upgrade [portname]

If you are familiar with Gentoo, this would be the equivalent of the revdep-rebuild command. See #17473 for more information.

Classification: easy to medium task
Programming languages: Tcl
Potential mentor: raimue

MacPorts Port for self-management

The MacPorts port should be the source for updating a user's MacPorts installation.

Currently the MacPorts port is used to build the .dmg installer for MacPorts that is used for the initial installation of MacPorts, and port uses the "selfupdate" mechanism for maintaining the MacPorts installation. The selfupdate mechanism is (at least not documented as such) not accessible through the MacPorts API and does not use the MacPorts mechanisms for maintaining ports

Classification: challenging task
Programming languages: Tcl and C
Potential mentor: blb

Check dependencies after destroot

MacPorts currently has trace mode to check which files are accessed during build and if they are in the dependency chain. This requires injecting the tracelib in all code that is run and interception all open calls and make checks on the pathnames which slows down the procedure. This task is about creating another feature for verifying the dependencies of a build.

A new phase would be created which is to be run after the destroot phase for checking dependencies. It would iterate over all binaries and dynamically linked libraries in the destroot which are going to be installed and check the recorded paths against the dependency chain. After that, it should report any files being linked against libraries not in the dependency chain.

This would be great to do a quick check if the dependencies are met without the effort from trace mode. It could also help to identify unnecessary dependencies. If this actually runs fast enough it could as well be enabled by default, although it should only be necessary for maintainers.

Classification: medium task
Programming languages: Tcl and C
Potential mentor: raimue

Binaries

MacPorts project does not provide binaries yet (installation of software without compiling them). This project consists in working in concert (or cooperatively) with whomever does (virtual chroot) to setup a mechanism to automatically build packages, send reports on failures and implement a distribution mechanisms to allow users to fetch binary packages. This task could extend to support universal binaries, cross-testing (building on an intel box and testing on a powerpc box) and extending the livecheck mechanism to automatically send reports when ports are updated.

See also MacPorts AutoBuild.

Classification: relatively challenging to challenging task
Programming language: Tcl
Potential mentors: TBD

Graphical user interface

Come up with a front-end for installing packages (or building ports, where no package exists) for naive end-users. See also ​drernie's post about MacPorts GUIs. The ​MacPorts.Framework and ​Pallet projects contain some of the already done ground work for building such a GUI.

Classification: major task
Programming languages: Tcl and any other language for the GUI part (e.g. ObjC)
Potential mentors: armahg

Images (Pkgview, depot-to-depot dependencies)

MacPorts implements what we call the Image mode where software are stored in a depot (e.g. /opt/local/var/db/dports/software/gawk/3.1.5_2/opt/local/bin/gawk). For the moment, this functions like an archive and files are hardlinked to their active location (/opt/local/bin/gawk). If port A depends on dynamic library B.dylib from port B, it actually links to /opt/local/lib/B.dylib. The idea of this task is to figure out a way for port A to be linked to the library in the depot and to work even if port B is not active. That is to say that if port foo depends on version 1.2.3 of port bar, it should be compiled and linked in such a way that it's wired to the depot location of bar, not the "activated" location. That will finally fix the fragility problem where deactivating port bar vers n-1 in order to install port bar vers n (because other things depend on n) won't also require breaking everything that relies on n-1. This mechanism also has additional advantages such as limiting the unavailability time to a minimum, especially when upgrading libraries every other package depends on (such as gettext).

Classification: challenging to very challenging task
Programming language: Tcl
Potential mentor: TBD

Portfiles

Sweep through all Portfiles and look for useful opportunities to add more built-in Tcl functions that make Portfiles more (usefully) terse, powerful, flexible or easier to write. I'm sure there is an entirely family of helper functions yet to be written here.

Classification: medium task
Programming language: Tcl
Potential mentor: TBD

Shell Environment

Add support for providing basic and port-provided environmental services to users in the ~/.profile, ~/.cshrc, and ~/.xinitrc files, so that instead of manipulating the user's .profile to modify certain paths, the installer could append "source /opt/local/etc/bash.rc" to the end of a user's .profile file and that bash.rc would source all the files in /opt/local/etc/bash.d.

This task alone is most probably not enough for the whole Summer Of Code.

Classification: easy task
Potential mentors: raimue

Automatic testing

MacPorts project currently includes a test framework to test features of the infrastructure. However, the tests do not cover all the code and they are not executed on an automatic basis. This task consists of extending the test framework and could be broadened to develop a code coverage technology for MacPorts to make the infrastructure more robust to future changes.

Classification: relatively easy to very challenging
Programming languages: Tcl, C
Potential mentor: raimue

MacPorts Web Application (MPWA)

A very good start has been made on a Web Application for MacPorts to serve as a basis for easier user submission and maintenance of ports, not to mention monitoring of port build status, browsing of ports, etc. This work is known as MPWA and is written in Ruby on Rails. This task is to complete the work on MPWA so that it is usable for day to day usage by the MacPorts community. Work is needed on user credentials and authentication, port dependency integration, port submission and tracking, etc. This is a very exciting project and can help MacPorts scale to support a larger community.

Read more about the MPWA design and model.

Classification: moderate, with good follow through vision, and architecture required
Programming languages: Ruby, perhaps a bit of Tcl
Potential mentor: jberry

Additional tasks

Task A1: Ports

• Porting of additional packages to MacPorts
• Cleanup and/or remove obsolete ports

Classification: medium task
Potential mentors: TBD

Task A2: Documentation and Website

• Improve MacPorts documentation
• Improve MacPorts website
• Custom Trac plugins

Note: Pure documentation proposals are not allowed by Google.

Classification: minor task
Programming languages: php, python
Potential mentors: TBD