In a cross-platform project, certain aspects of an SCM system take on added importance. In this chapter, the author describes the tools, including CVS, Bugzilla, Tinderbox, and Patch, that were most important to developing his Netscape and Mozilla projects.
A software configuration management (SCM) system consists of tools and processes used to manage the source code of a project and to assess its state. With these tools, management and developers can do the following:
Peruse the source code managed by the SCM system
Obtain a local copy of the source code
Submit modifications made to the source code by developers
Understand which changes have been made to the source code by developers
Determine the state of the source code (for example, whether it compiles)
Log and track defects associated with binaries created from the source code
In a cross-platform project, certain aspects of an SCM system take on added importance. In this chapter, I describe the tools that were most important to Netscape and Mozilla in this regard:
CVS, the Concurrent Version System, which was used to maintain and manage a central copy of the Netscape/Mozilla source code
Bugzilla, used to track defects in programs generated from the source code stored in CVS
Tinderbox, used to determine the state of the source code as changes were made to the copy stored in CVS
Patch, a tool that fosters the distribution and communication of changes among developers (in particular, between a developer and code reviewers) prior to it being permanently stored in CVS
These tools, combined with some best practices for using them that I describe in this chapter, helped greatly in ensuring that Netscape shipped cross-platform products that were similar in features and overall quality, and did so on the same schedule.
Item 11: Use a Cross-Platform Bug Reporting and Tracking System
A major component of a cross-platform toolset is the bug reporting and tracking system (which I refer to as a "bug system" here for brevity). A bug system is used by developers and testers to report defects and issues encountered during the software development and testing phases of a project. In general, a bug system should allow the reporter to specify the problem encountered, identify the context or state of the system at the time the bug was discovered, and list the steps required to reproduce the bug. The bug system also must allow for the tracking of any issues it contains. In terms of tracking, bugs generally go through the following states:
New. A bug that has been discovered, but has not been investigated by a developer.
Assigned. The developer acknowledges the bug and is investigating.
Resolved. The developer has fixed the bug, or has some other resolution (for example, unable to reproduce the problem, or the feature is working as designed).
Verified. QA/test has acknowledged the resolution of the developer, and has verified it to be correct.
In addition, a bug can be in the reopened state, an indication that a once-verified bug has resurfaced in testing after originally being verified by QA.
Finally, a bug system should allow someone to specify the relative priority of bugs filed against a product. Initially, this will be the person filing the bug, but ideally, it is done in a "triage" session, with participation of the following teams: development, QA/test, and product management. Tracking priorities is not easy, it takes discipline for people to sit down for an hour or two and grind through a list of bugs, but doing so allows developers to prioritize their work, and allows those who are making ship/no-ship decisions the opportunity to objectively decide what state the project is in.
When it comes to cross-platform development, you should always look for a couple of attributes and features when selecting a bug system for use in your project.
Accessibility
Perhaps the most important cross-platform attribute you should look for when selecting a bug system is accessibility. In a cross-platform development project, everyone will have his or her preferred development platform (see Item 1). For some developers, it will be Mac OS X, and for many it will be Windows. If the bug system is not accessible to everyone on the team via their native platforms, it risks not being used by those who would rather not boot into one of the operating systems that the bug system does support. Therefore, the bug system itself needs to be cross-platform. And, it must support all of your tier-1 platforms.
These days, by and large, the accessibility requirement is best met by using a Web-based bug system. Web browsers are available for every platform, including PDAs and mobile phones. Bug reporting/tracking systems based on LAMP (Linux, Apache, MySQL, PHP) or Java/JSP are available.
Ability to Track Platform-Specific Bugs
In some cases, a bug will be reproducible on all platforms, and in other cases, only a subset of the supported platforms will exhibit the given problem. It is critical that the platforms affected by the problem be tracked. The bug system should allow the person filing the bug, or even someone updating the bug at a later time, to specify the platform(s) affected by any given bug. Doing so will allow someone searching the bug database to specify a subset of the supported platforms as search criteria (for example, "find all assigned Linux bugs"). By specifying the platforms as part of the search criteria, platform specialists will be able to quickly identify bugs that affect their platform, and management will be able determine the number of open (and resolved) issues on a per-platform basis.
Bugzilla
Most of my experience with bug reporting systems has been with a bug tracking system named Bugzilla—yet another result of the Netscape/Mozilla project. Bugzilla is implemented as a Web application, allowing the database to be viewed from any platform that supports a Web browser. Bugzilla has been in active development for years, and is used by hundreds of organizations. Because Bugzilla originated during the development of the cross-platform Netscape/Mozilla system (it replaced a Netscape-internal bug system in use during the development of the 4.x browser called bugsplat), it has always supported cross-platform development directly.
Installing Bugzilla is pretty straightforward, and is well documented. A basic installation of Bugzilla can be done in about an hour, depending on your setup. (That was my experience on a stock Red Hat Fedora Core 4 system, and your results may vary.)
The following instructions are based on a Fedora Core 4 setup, using Apache and MySQL. (The default versions of Apache, Perl, and MySQL that come with FC4 are suitable for use with Bugzilla 2.22.)
Visit www.bugzilla.org, and download the latest stable release (2.22 as of this writing) onto the Linux machine that you will use to host the Bugzilla server. Then:
