How to Help Squish Bugs
While adding new features is an important part of improving Wine, bugs directly affect the program's quality and user experience. There are several ways to help make Wine more robust with better performance, and most of them require little to no programming experience.
Working with Bugzilla
Wine uses Bugzilla (external link) to manage BugReports by users and streamline communication between testers and developers. By providing a web interface for easily editing and querying a bug database, the entire community can work together to fix problems as quickly as possible.
Those that don't mind more bureaucratic tasks might enjoy helping with BugTriage
Sometimes, certain "challenges" are proposed to coordinate work on bug triage or specific problems:
Wine itself has a set of ConformanceTests that can be run automatically on Unix or Windows to test for bugs on your specific system
Many popular open-source applications also have their own UnitTestSuites that can help find and narrow down bugs in Wine
Sometimes new changes in recent versions of Wine unexpectedly revive old bugs, known as regressions. If you are comfortable with using Git and compiling Wine from source, you can do rapid RegressionTesting and help narrow down bugs to specific patches.
If you want to track down bugs in the code itself (and possibly contribute fixes), there are many pages on the wiki with useful advice. If you're looking for some ideas or information on how to actually track down a bug:
Also look at the list of KnownIssues. These are major bugs that either require major changes or have been traced upstream.
There is a short list of DeveloperExamples that show the process behind finding and fixing real bugs
Various debugging tricks that may be useful such as a patch for toggling debug traces or remotely debugging a Wine session from Visual Studio
There are also pages on debugging specific features in Wine, such as:
Improving the Performance of specific programs in Wine
TestingLanguages to make sure dialogs display properly
If you want to want to write or modify some of Wine's automated tests, these pages will probably come in handy:
Working with BuildBot, which automatically checks submitted patches for build errors
Using the WineTestBot, which allows changes specifically to Wine's test suite to be checked automatically on several Windows VMs.
Some other miscellaneous pages related to quality assurance:
A list of AvailableHardware (specifically GPUs) that various contributors have offered to use for testing patches.