Launchpad helps you to appraise a bug by giving you a calculated measure — called bug heat — of its likely significance.
You can see bug heat in bug listings, and also on individual bug pages, as four flames: the more flames that are lit, the higher the bug's heat.
Launchpad works out how many flames to light by calculating a bug heat score and then seeing how that compares with the bug heat of other bugs for that project. If you want to see the bug heat score itself, hover your mouse over the flames icon.
To calculate the bug heat score, Launchpad looks at the bug's:
Here's exactly how Launchpad calculates the bug heat score. First Launchpad gives the bug a base score:
| Attribute | Calculation |
|---|---|
| Private | Adds 150 points |
| Security issue | Adds 250 points |
| Duplicates | Adds 6 points per duplicate bug |
| Affected users | Adds 4 points per affected user |
| Subscribers (incl. subscribers to duplicates) | Adds 2 points per subscriber |
Next, it adjusts the score depending on how active the bug is:
| Nature of recent activity | Calculation |
|---|---|
| Bug has been active* within the past 24 hours | Add 25% of the project's hottest bug's score divided by the number of days since the first activity on the bug in question |
| Bug has not been active* in within the past 24 hours | Subtract 1% of the bug heat score for every day of inactivity |
* Activity is either a comment posted or some other update to the bug report.
Some bug statuses will also affect the overall score:
| Status | Affect on bug heat score |
|---|---|
| Fix Released | Reduces the total bug heat score to zero |
| Invalid | |
| Won't Fix | |
| Expired |
To view the code that calculates bug heat, look for calculate_bug_heat in the file trusted.sql