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57 votes

What is it called when several bugs cancel each other out?

I call them masked bugs. Bug 1 (the erroneous subtraction) is masked by bug 2 (the erroneous addition). Ideally, they would be caught by unit testing - since unit tests should be reporting whether or ...
Kate Paulk's user avatar
  • 31.5k
30 votes

What is it called when several bugs cancel each other out?

An auditor or accountant would describe this as an incidence of "Compensating Errors" - it's probably something which is much more common in both of those fields. I think the term describes the ...
Rob Richardson's user avatar
24 votes

What is it called when several bugs cancel each other out?

I've always said such code "works by coincidence". If you say the code is broken or has a bug, people tend to push back because it appears to work to a casual observer. "Works by coincidence" ...
bta's user avatar
  • 391
17 votes

How can I isolate bugs of users that we are not able to replicate?

You have intermittent failures Welcome to the crowd. In my experience they are the norm and the bane of Quality Engineering. So first off - accept that and start making resources available for it. ...
Michael Durrant's user avatar
13 votes

How can I isolate bugs of users that we are not able to replicate?

"How to Investigate Intermittent Problems" by James Bach provides a very thorough treatment of the subject. Here's an outline of his 92 suggestions: If the bug exists, it has a cause: Possibility ...
alexanderbird's user avatar
12 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

I probably first encountered this in the perl community, where the advice to use warnings "all"; and use strict; is so common. My guess is that I first read this in "effective perl programming" by ...
Matthew Heusser's user avatar
9 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

An early tool which generated warnings, with the intention to have them fixed by the programmer as if they were errors, was Lint. Stephen Johnson. Lint, a C program checker. Computer Science ...
Klaws's user avatar
  • 241
9 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

I totally agree with Neils, and I'd like to address the question of whether or not this post belongs on this Testing site. Good testing starts long before any code is written, especially when it ...
Gerald M Weinberg's user avatar
6 votes
Accepted

On what metrics are the debugging skills of an interview candidate assessed?

I would suggest also: Try logging in on your friends computer and seeing if you can upload from there. Try having your friend log in on your computer and uploading a pic from there Try using (send to ...
Michael Durrant's user avatar
6 votes

How can I isolate bugs of users that we are not able to replicate?

Analyse from different perspectives to find the exact cause I am assuming that you are trying to debug the issue in the same environment where it was reported. Few things that should be considered ...
Aalok's user avatar
  • 1,732
5 votes

How can I isolate bugs of users that we are not able to replicate?

Here is what I instruction my developers to do: 1) add logging; allow the user to select advanced logging. If turning on logging "solves" the problem then it is a timing issue. We add logging to ...
Be Kind To New Users's user avatar
5 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

If anything, it was the reverse of this -- the culture started letting errors and warnings stay in, more and more. Back in punch card days, access to the punch card machines to read your deck of ...
Patricia J. Hawkins's user avatar
5 votes

How can I isolate bugs of users that we are not able to replicate?

Apart from the technological aspects, you might need to consider organizational aspects as well. You will, most likely, have a ticket (a bug report) which remains open/assigned (unresolved) for quite ...
Klaws's user avatar
  • 241
5 votes

Most famous concurrency bugs?

There are two that come to mind: Therac-25 and the Northeast Blackout of 2003. The Therac-25 was a radiation therapy machine; there was a race condition that could cause the high-power electron beam ...
Kevin McKenzie's user avatar
5 votes
Accepted

Working just on branch or line coverage could prevent us from finding which defect?

Achieving branch coverage is possible but it doesn't mean complete testing. Indeed, no amount of fact-checking can achieve complete testing, because fact-checking is only one of the activities of ...
João Farias's user avatar
  • 10.9k
5 votes

What is it called when several bugs cancel each other out?

I simply call them bugs that cancel each other, and I doubt if there is any special way to find or avoid them, and whether any special research was done on it (I tried Google Scholar and haven't found)...
Rsf's user avatar
  • 7,091
4 votes

On what metrics are the debugging skills of an interview candidate assessed?

In addition to the great answer Michael provided I would say the following. Frankly speaking the question misses some important specific like "on which exactly step does the process fail". Since you ...
Alexey R.'s user avatar
  • 11.6k
4 votes

How to teach test automation engineers to use a debugger

Excellent question. Debugging is a basic skill programmers should have. Many testers lack programming skills because companies throw people with no or only little programming experience into test ...
dzieciou's user avatar
  • 10.5k
4 votes

What is it called when several bugs cancel each other out?

I've called this "an even number of bugs". I believe that the term can be attributed to my Calculus professor, who once made "an even number of mistakes" on the board. Examples of "an even number of ...
dotancohen's user avatar
4 votes

What is it called when several bugs cancel each other out?

In quantum chemistry, a related phenomenon is called "cancellation of errors"
mrupp's user avatar
  • 141
3 votes

How can I isolate bugs of users that we are not able to replicate?

Here are some ideas: Strongly agree with logging! With time stamps including milliseconds (big difference between events A at 01:23:45.999 and B at 01:23:46.000, vs. A at 01:23:45.000 and B at 01:23:...
Technophile's user avatar
3 votes
Accepted

Fix All Warnings And Errors: what is the history of this code quality tactic?

Steve McConnell writes in Code Complete (1993): p69: Eliminate the causes of all compiler errors and warnings. Pay attention to what the compiler tells you about your code. A lot of warnings often ...
nobody's user avatar
  • 150
3 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

I wonder if it is relevant who said it first. I expect it historically to be more in line with many different teams running into similar issues with warnings and errors before they wrote it down as a ...
Niels van Reijmersdal's user avatar
3 votes

ROBOT FRAMEWORK: [Error] Parsing ___.robot failed: Data source does not exist

"data source does not exist" simply means that you gave a filename to robot, and robot can't find that file. For example: $ pybot /path/to/non-existent/file [ ERROR ] Parsing '/path/to/non-existent/...
Bryan Oakley's user avatar
3 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

One part of the Ruby on Rails history over the last ten years is that frequently changes are marked with deprecation warning messages in one version before backward compatibility is removed altogether ...
Michael Durrant's user avatar
3 votes

What is it called when several bugs cancel each other out?

If you are dealing with the case @jonsharpe described above, you can create examples with the components in isolation. If they are not decoupled, you probably have a testability problem that is ...
João Farias's user avatar
  • 10.9k
3 votes

What is it called when several bugs cancel each other out?

Two errors which perfectly cancel each other out are possible only in the most theoretical sense. On any real computation machine, such a perfect cancellation is not possible. Consider the very ...
UnLogicGuys's user avatar
3 votes

What is it called when several bugs cancel each other out?

Most of the times that I have met this sort of thing it has not been bug in function Y cancels but in function X - it has been bug in function X compensated for by incorrect patch in function Y, i.e. ...
Steve Barnes's user avatar
2 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

Practices of an Agile Developer, Subramaniam & Hunt, 2006. Page 137 has this... Just because your compiler treats warnings lightly doesn't mean you should. Treat warnings as errors. Checking in ...
roblogic's user avatar
  • 171
2 votes

Fix All Warnings And Errors: what is the history of this code quality tactic?

Since you asked for anecdotal, this is about as anecdotal as it gets. This is a very opinion based question. First: Fix all warnings and errors. Do not tolerate any error messages Can be ...
Chris Schneider's user avatar

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