All changes to Sage source code have to go through the Sage trac development server. The purpose of the Sage trac server is to
There is also a wiki for more general organizational web pages, like Sage development workshops.
Thus if you find a bug in Sage, if you have new code to submit, want to review new code already written but not yet included in Sage, or if you have corrections for the documentation, you should post on the trac server. Items on the server are called tickets, and anyone may search or browse the tickets. For a list of recent changes, just visit the Sage trac timeline.
There are two avenues to prove to the trac server that you are who you claim to be. First, to change the ticket web pages you need to log in to trac using a username/password. Second, there is public key cryptography used by git when copying new source files to the repository. This section will show you how to setup both.
You first need to open an account if you want to change anything on the Sage trac server, even if you just want to comment on a ticket. Part of the process is to prove that you are a human to keep spam at a minimum. To get an account read the developer manual (this document) and then send an email to firstname.lastname@example.org that contains all of the following:
Your trac account also grants you access to the sage wiki. Make sure you understand the review process, and the procedures for opening and closing tickets before making changes. The remainder of this chapter contains various guidelines on using the trac server.
The git installation on the development server uses SSH keys to decide if and where you are allowed to upload code. No SSH key is required to report a bug or comment on a ticket, but as soon as you want to contribute code yourself you need to provide trac with the public half of your own personal key. In recent versions of Sage, you can use Sage to generate an upload an SSH key
sage: dev.upload_ssh_key() The trac git server requires your SSH public key to be able to identify you. Upload "/home/vbraun/.ssh/id_dsa.pub" to trac? [Yes/no] y Trac username: user Trac password: Your key has been uploaded.
You can also manually generate an SSH key and upload it to trac. This is described in the following two sections.
If you don’t have a private key yet, you can create it with the ssh-keygen tool:
[user@localhost ~]$ ssh-keygen Generating public/private rsa key pair. Enter file in which to save the key (/home/user/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /home/user/.ssh/id_rsa. Your public key has been saved in /home/user/.ssh/id_rsa.pub. The key fingerprint is: ce:32:b3:de:38:56:80:c9:11:f0:b3:88:f2:1c:89:0a user@localhost The key's randomart image is: +--[ RSA 2048]----+ | .... | | .. | | .o+ | | o o+o. | |E + . .S | |+o . o. | |. o +.o | | oB | | o+.. | +-----------------+
This will generate a new random private RSA key in the .ssh folder in your home directory. By default, they are
The ssh-keygen tool will let you generate a key with a different file name, or protect it with a passphrase. Depending on how much you trust your own computer or system administrator, you can leave the passphrase empty to be able to login without any human intervention.
If you have accounts on multiple computers you can use the SSH keys to log in. Just copy the public key file (ending in .pub) to ~/.ssh/authorized_keys on the remote computer and make sure that the file is only read/writeable by yourself. Voila, the next time you ssh into that machine you don’t have to provide your password.
If you think you have found a bug in Sage, you should first search through the following Google groups for postings related to your possible bug:
Maybe the problem you have encountered has already been discussed. You should also search the trac server to see if anyone else has opened a ticket about your bug.
If you do not find anything, and you are not sure that you have found a bug, ask about it on sage-devel. You might be asked to open a new ticket on the trac server. As mentioned above, you need an account to do this. To report a bug, login and click on the “New ticket” button. Type a meaningful one-liner in the “Short summary” box, with more information in the larger box below. You should include at least one explicit, reproducible example illustrating your bug (and/or the steps required to reproduce the buggy behavior). You should also include the version of Sage (and any relevant packages) you are using, and operating system information, being precise as possible (32-bit, 64-bit, ...).
Between the “Summary” and “Full description” boxes, there is a place to choose the “Type” of the ticket: “Defect”, “Enhancement”, or “Task”. Use your best judgment here; a bug should probably be reported as a “Defect”.
Also pick a component for your bug; this is sometimes straightforward. If your bug deals with Sage’s calculus implementation, choose “calculus”. If it is not obvious, do your best. Choose a milestone; if you are not sure what to choose, just choose the numbered version of Sage from the menu (“sage-5.10”, for example). Type in some helpful keywords. In the box labeled “Assign to”, type “somebody” if you are not sure what else to do.
Hit the “Preview” button to make sure everything looks okay, and then hit “Submit ticket”.
If you do not have an account on the trac system to report directly, you are still encouraged to report any possible bug to the sage-devel mailing list at email@example.com. The list is moderated for new users and requires subscription. In your bug report to sage-devel, make sure to include the following information:
Thank you in advance for reporting bugs to improve Sage in the future!
In addition to bug reports, you should also open a ticket if you have some new code which extends Sage’s capabilities. If you have a feature request, start a discussion on sage-devel first, and then if there seems to be general agreement that you have a good idea, open a ticket describing the idea.
When you consider opening a new ticket, please bear the following points in mind.
When you open a new ticket or change an existing ticket, you will find a variety of fields that can be changed. Here is a comprehensive overview:
If a component of Sage produces a mathematical error, you should open two tickets: a main ticket with all available details, and also a “stopgap” ticket. This second ticket should have a patch which will be merged into Sage if no one fixes the main issue; this patch should print a warning when anyone uses the relevant code. To produce the warning message, use code like the following:
from sage.misc.stopgap import stopgap stopgap("This code contains bugs and may be mathematically unreliable.", TICKET_NUM)
Replace TICKET_NUM by the ticket number for the main ticket. See trac ticket #12699, for example. On the main trac ticket, you should also enter the ticket number for the stopgap ticket in the “Stopgaps” field. Stopgap tickets should be marked as blockers.
If mathematically valid code causes Sage to raise an error or crash, for example, there is no need for a stopgap. Rather, stopgaps are to warn users that they may be using buggy code; if Sage crashes, this is not an issue.
If you manage to fix a bug or enhance Sage you are our hero. See Sage Development Process for making changes to the Sage source code, uploading them to the Sage trac server, and finally putting your new branch on the trac ticket. The following are some other relevant issues:
All code that goes into Sage is peer-reviewed, to ensure that the conventions discussed in this manual are followed, to make sure that there are sufficient examples and doctests in the documentation, and to try to make sure that the code does, mathematically, what it is supposed to.
If someone (other than you) has posted a git branch for a ticket on the trac server, you can review it! Look at the branch diff (by clicking on the ) to see if it makes sense. Download it (see Reviewing) and build Sage with the new code. Now ask yourself questions such as the following:
If the answers to these and other such reasonable questions are yes, then you might want to give the patch a positive review. On the main ticket page, write a comment in the box explaining your review. If you don’t feel experienced enough for this, make a comment explaining what you checked, and end by asking if someone more experienced will take a look. If you think there are issues with the patch, explain them in the comment box and change the status to “needs work”. Browse the tickets on the trac server to see how things are done.
“The perfect is the enemy of the good”
The point of the review is to ensure that the Sage code guidelines are followed and that the the implementation is mathematically correct. Please refrain from aditional feature requests or open-ended discussion about alternative implementations. If you want the patch written differently, your suggestion should be a clear and actionable request.
Only the Sage release manager will close tickets. Most likely, this is not you nor will your trac account have the necessary permissions. If you feel strongly that a ticket should be closed or deleted, then change the status of the ticket to needs review and change the milestone to sage-duplictate/invalid/wontfix. You should also comment on the ticket, explaining why it should be closed. If another developer agrees, he sets the ticket to positive review.
A related issue is re-opening tickets. You should refrain from re-opening a ticket that is already closed. Instead, open a new ticket and provide a link in the description to the old ticket.
One Issue Per Ticket: A ticket must cover only one issue and should not be a laundry list of unrelated issues. If a ticket covers more than one issue, we cannot close it and while some of the patches have been applied to a given release, the ticket would remain in limbo.
No Patch Bombs: Code that goes into Sage is peer-reviewed. If you show up with an 80,000 lines of code bundle that completely rips out a subsystem and replaces it with something else, you can imagine that the review process will be a little tedious. These huge patch bombs are problematic for several reasons and we prefer small, gradual changes that are easy to review and apply. This is not always possible (e.g. coercion rewrite), but it is still highly recommended that you avoid this style of development unless there is no way around it.
Sage Specific: Sage’s philosophy is that we ship everything (or close to it) in one source tarball to make debugging possible. You can imagine the combinatorial explosion we would have to deal with if you replaced only ten components of Sage with external packages. Once you start replacing some of the more essential components of Sage that are commonly packaged (e.g. Pari, GAP, lisp, gmp), it is no longer a problem that belongs in our tracker. If your distribution’s Pari package is buggy for example, file a bug report with them. We are usually willing and able to solve the problem, but there are no guarantees that we will help you out. Looking at the open number of tickets that are Sage specific, you hopefully will understand why.
No Support Discussions: The trac installation is not meant to be a system to track down problems when using Sage. Tickets should be clearly a bug and not “I tried to do X and I couldn’t get it to work. How do I do this?” That is usually not a bug in Sage and it is likely that sage-support can answer that question for you. If it turns out that you did hit a bug, somebody will open a concise and to-the-point ticket.
Solution Must Be Achievable: Tickets must be achievable. Many times, tickets that fall into this category usually ran afoul to some of the other rules listed above. An example would be to “Make Sage the best CAS in the world”. There is no metric to measure this properly and it is highly subjective.