How to Write a Good Bug Report, use RIMGEN


RIMGEN is an acronym and mnemonic (or memory aid) to help us remember the elements of a good bug report. It can be used to help anyone write a better bug report or review existing bug reports looking to make improvements. It is also the updated version of RIMGEA (as detailed in the Bug Advocacy Workbook) and I think it makes a little more sense.

In general my preference with reporting bugs is to:

  1. Work with a developer to get them fixed, either by mentioning it passing or pairing with them. By far the most effective way to get bugs fixed.
  2. Fix it myself, although most of these are very simple bugs.
  3. Write a bug report. These are good instructions for that process.

How to Write a Good Bug Report

Writing a bug report seems simple on the surface. People in many roles (programmers, testers, internal and external customers, analysts) write them without much, if any, practice. Although we’ve all seen those bug reports come in without much detail or context and guess what? They don’t get fixed. Just because something is easy to do doesn’t mean it is easy to do well.

We’re writing a good bug report to get a problem fixed. Programmers are busy people, with lots of things going on and plenty of demands on their time. They don’t want to look at a bug report that doesn’t make sense, requires too much work on their part to understand or is offensive. Let’s be honest, if a bug is fairly obvious a programmer isn’t likely to need much information, motivation or influence to fix it. They might not even require a bug report to be written (mention it in passing or through slack). Those aren’t the bugs we are interested in advocating for. We’re advocating for the bugs or problems we understand to be important (for some reason) but might not be easily understood as such.

How do we advocate for bugs to be fixed? We develop reports that clearly communicate the problem, reflect the problem in a harsh but honest way so that some stakeholder realizes the risk and wants to them fixed. Just reproducing the problem might not always be enough. We want to make programmers want to fix the bug by influencing their decision, we’re selling them on fixing the bugs. To “sell” someone on fixing the bugs we need to write a good report.

To help us understand the elements of a good report we can use the heuristic RIMGEN.

RIMGEN:

R – Replicate it. When writing a bug report we should include enough information to get the bug fixed including the steps or conditions necessary to replicate the problem on another machine. The lecture recommends using at least 2 different machines – a powerhouse computer and another less powerful / resource constrained machine. (Virtual environments might work as well.)
I – Isolate it. After we’ve replicated the problem, we want to identify the shortest number of critical steps necessary to replicate the problem by eliminating some of the variables. Clarity is the goal. We also want to make sure to write up only one problem per report so we don’t get into a situation where one part of the bug is fixed and the other remains open. Example: OpenOffice Impress crashes after importing a file, but our reproduction is 25 steps long. We do some more testing that helps us eliminate some variables until we’re able to get the problem replicated in 6 steps.
M – Maximize it. Maximizing the problem means doing some follow up testing to see if we can find a more serious problem than the one we were originally going to report. Follow up testing can consist of varying our behavior, our environment, our inputs or even our system configuration. The more serious the problem the more likely (or easier) it will be to convince someone to fix it. Example: We find a problem in OO Impress where it won’t import old PowerPoint files; the application just won’t respond. After some follow up testing we find Impress actually crashes if we use an old PowerPoint file over a certain size.
Maximizing a bug (or follow up activities as it’s also known) is one of the more interesting and time consuming aspects of writing a bug report. There’s quite a bit of detail just in the four categories of variables: vary our behavior, vary our environment, vary our data and vary our system configuration and for those interested Markus Gartner goes a little more in-depth about each in this post.
G – Generalize it. Generalizing the bug means seeing if the problem affects more people in more ways than we originally thought. If the bug was a corner case maybe we can un-corner it, show that it occurs under less extreme conditions. (replicating on a broader range of systems?) Example: Same problem as above in OO Impress where it crashes when we try to import old PowerPoint files over a certain size. We vary the data (input) and find out Impress actually crashes when we try to import any file type over a certain size. Now the problem looks really bad and affects more users than just older PowerPoint users.
E – Externalize it. Switch the focus of the report from the program failing to the stakeholders who will be affected by it and show how it will affect them. (Historical review?) Example: OO Impress crashing when importing any file type of a certain size will stop all users from importing comparable application files (like from PowerPoint). This could prevent new users from downloading and installing the application and even turn off existing users who rely on the compatibility.
N – Neutral Tone. Make sure the bug report is easy to understand and that the tone of the report is neutral so as not to offend anyone reading it (perhaps the developer who created the bug) and/or discredit your reputation as the bug reporter (at least in the eye of the reader).

 

BUG TITLES AND SUMMARIES

To help us communicate (and “sell”) the problem clearly in bug titles and summaries we can use the “Fails, When Protocol”. “Fails, When” says describe the failure first and then when that failure happens second.

For example in Bug Advocacy we look at two (apparently) well known problems in Microsoft Paint 95 (I think that’s the version) related to cutting and pasting from a zoomed section. When I wrote up my problem summary (before understanding the protocol) it came out as: “Cutting (Ctrl-X) a selected area while zoomed causes inconsistent behaviors.” The problem with this summary was it was too vague, contained minor details about the problem and although I spotted two bugs I tried to combine the two summaries into one. If I had used the “Fails, When” protocol a more appropriate set of bug titles might have been: “Cut doesn’t cut (freehand, zoom)” or “Cuts the wrong area (freehand, zoom, resize window)”.

To help us avoid being vague when summarizing and communicating a problem it’s important to consider how much insight the title or summary gives you into the nature, severity, or scope of the problem; does it over emphasize minor details (especially for the bug title)?

A Few Other Things:

  • Looking for something a little more portable? Checkout my Bug Reporting Guidelines document.
  • This is an update of my previous post “How to Write a Good Bug Report (and be a Bug Advocate)” with some slight alterations.
  • Design vs coding bugs are slightly different and have a different emphasis using RIMGEN. I hope to address this later in a separate article.
  • Advocating for a bug to be fixed is not an invitation to be sleazy or aggressive in your reporting. We are trying to influence a decision based on our research and understanding, not trying to ruin our credibility by pushing something the business has no desire to fix.