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Tips and Tricks - How to reproduce the bug if it is hard to reproduce?

Many time I observed that testers are talking about that bugs was “Not Reproducible” and I am not able to find the exact steps. Generally if the defect is unable to reproduce then they are making them into “Not Reproducible” category. However as a tester I am intentionally calling this as “Hard to Reproduce” because I believe each bug is reproducible in specific situation, it just matter of finding the exact steps to reproduce.

In testers carrier almost every tester face “Hard to reproduce” bug. Every good tester is like to reproduce steps for the bugs which are hard to reproduce. But some testers are panic when the bug is not getting reproducible even after executing similar steps. Following are the few sample responses which I heard from testers:

  • Bug is taking lot of time for the investigation.
  • Sometimes the issue is observed only after when we re-start the application.
  • This bug is not-producible always. So we have captured the log.

In this article lets discuss following points which I likely to use while look for the “Hard to Reproduce” Bug.


1. Watch every action; be alert!

Here I want to tell you that you should be sharp-eyed like eagle and eager to know about each and every action while trying to corner the bug. Need more observation skills on the application behavior under test. Keeps watch on any doubtful process running on the system. The status bar is in progress from long time, partially loaded dialog box, slowness around the application, some additional log is getting added in the log etc. “Always be on your toes” If you are able to figure out what is the problem in first place, then it will definitely help you for bug hunting.

How to reproduce the bug if it is hard to reproduce


2. Look for Patterns!

Best way to reproduce the bug is to identify the patterns because the “Bug likes Patterns”. Search for the Patterns around the similar type of bug if any and if you are successful to identifying pattern then you will definitely able to identify the bug.

I want to share my experience around this. Last week, when I was doing bug triage (reviewed the bug) reported by my team member and observed that the issues was added under “Not reproducible” category. So I am curious about such bugs, so I checked the additional information added in the ticket saying the issue about “Unknown database error”. So I thought of searching the similar defect might have been already logged by the team members. In fact I am able to find the defect around “Unknown database error”. When I digg around that defects then realize that the issue is related to special chars (single quote) added in the input. This is what the important information received from the cousin bug. When I tried with special chars then I was able to reproduce the “Unknown database error”.


3. Note down the things you are doing while testing!

List down the thing which you are doing while reproducing the bug like testing environment, test data you are using, database configurations, any other setting you made etc. This will help you to reproduce the bug. Consider a case where you followed some steps and issue got reproduce, however you nothing noted down, then it would be hard to replicate the same steps again. So keep in mind to Capture the complete Test Environment.


4. Not Only Trust But Also Always Verify Bugs!

While doing Hard to reproduce bugs, please don’t trust without verifying the bug. Get the defect report for your reference. While reproducing hard to reproduce bug, do verification by your own and check if things are working as what they suppose to.


5. Have patience! – (they won’t occur easily)

While testing such a “Hard to Reproduce” bug you have to be more patience, which will lead you to get the exact steps to reproduce. Have patience is the key to success while hunting such bugs.



If the bugs are complicated then it bound to take more time to reproduce. If there are many such issues added in the queue then I recommend prioritizing the bugs, the critical bugs must be picked first reproduce. Try to capture few things while reproducing bug like test data, server logs, system logs, applications logs, screen shots etc. Please try to capture the story around the issue and not just steps. The resource time might be constraint in this case, so talk with your manager on this if it is taking more time.

Do you have any other good method on “How to reproduce hard to reproduce bug” then please share in the comments below.



8 comments to Tips and Tricks – How to reproduce the bug if it is hard to reproduce?

  • Kishori

    Very helpful and informative!!

  • vidya

    Tip and tricks explained in short and sweet way.

  • Rajat

    Nice suggestion. Its a good practice to find hard to reproduce bug as they intent to be more difficult and challenging.

    One small suggestion if you find any other bug close to hard to reproduce then try to link them so that next time you can have more option to go through and resolve such issues quickly.


  • Niddhi

    Awesome Job.. Great, Motivated:)

  • Canon

    You made tester as professional, Thanks a lot. Very interesting and awesome article.

  • Nitin Tilekar

    One small suggestion: Not only capture the screen shots. Try to capture the video while you are testing the software. It will help to investigate bug & helpful for whole project team. Use video capture tool.

  • Natarajan

    I found one bug and also having the screenshot of that. but still now I couldn’t able to reproduce that bug 🙁 🙁

  • Paul

    It’s possible worth a mention that the amount of time you might spend searching for this issue would depend on the end result – we need to be very careful of spending large amounts of time tracking down hard to repro issues when the end issue isn’t that valuable (in terms of impact to product)

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