What's the dumbest bug you caused yourself

Editing in development environment while watching another environment for changes that never come. I'm afraid to say I've wasted way too much time wondering why nothing worked.

I dropped test coverage by over 60%, all because I left a setting that focused on running a single test and only that test.

This happened today.

One time I was writing some code and I heard the Mac trash can sound in my headphones and it confused me for a second, but I kind of shrugged it off. A little later I went to commit some code to production and it was a tiny fix and I did git add . and made the push without thinking much. Then I went off to do some other things.

A little later I notice that A CRITICAL IMAGE IS MISSING and that's when I realized what the trash can sound was. I accidentally sent something to the trash as my computer lagged and I clicked some keys while it was frozen.

I HEARD THE TRASH CAN sound and when I put two and two together it was major face palm.

Very sloppy.

Not a big deal but i wrote
curl_setopt($handle, CURLOPT_HTTPHEADER, "Authorization : something");
instead of
curl_setopt($handle, CURLOPT_HTTPHEADER, "Authorization: something");
took me three days and stackoverflow to notice it

The biggest face-palm bug I've faced was while working on a language runtime. I was implementing a method aliasing feature that, if working correctly, would extract a method from one object and inject it into another. I coded up a solution that should have worked, fired up a REPL, and attempted to hit the new aliased method.

I was promptly greeted by an error with the message "This method does not exist." Crud!

I went back and reviewed my implementation. I tried adjusting some things, moving allocations and dereferencing pointers slightly differently, and yet each time I got the same answer: "This method does not exist." I put in some debug logging statements, but everything looked correct. I stepped through the whole process in a debugger, and still everything looked correct.

At a loss, I randomly decided to look at the implementation of the method I was attempting to alias. Since it was a library method, and not part of the project I was working on, I had to go check out the code and dig in. Eventually, after working out all the complex inheritance and class-cluster implementation details, I found the source of the specific method I was working with. It was, in effect:

fprintf(stderr, "This method does not exist.");

my cheapest bug in the code:
back in 2005 I needed to send email to 300 customers in two for loops..
so I sent 300 identical emails to each customer, because of index error in second for

This one time, in band-camp, my login authentication banned the IP address of a user who had 3 consecutive failed login attempts. Out of nowhere, the entire e-commerce site was "down". Needless to say, It took me an entire day to figure out that one of the managers had forgotten his password and banned the outbound IP address for the entire organization. Ugh

I accidentally mis-wrote some CSS, so the animation from an svg loading element bled over to all the svg's on the page. The feature we were working on involved a rating page with a bunch of yellow stars (think amazon reviews) that now all spun around. It delighted everyone and they made me show it to the executive in charge of the whole division.😅

I developed a company-internal social application with LDAP authentication.
I used a code snipplet.
As it turned out, any username with empty password worked just fine. The code snipplet would simply skip password check for "undefined" empty password.
:-o

it took me an hour to figure out why i only sometimes got a certain thing to happen (i can't remember what it was, so let's call it a popup). i'd go through the process of doing what needs to be done and only sometimes the popup worked and i couldn't figure it out.

turns out i shot myself in the foot when i used

if (variable) {
...
}

"that won't work you knob! 0 is a valid value!"

Spent two days debugging a seemingly impossible freeze-crash.

Day two, my non-programmer mother said "I bet you forgot a semicolon somewhere."

Ten minutes of desk-checking later, yup, there it was. Missing semicolon in a for loop, making it infinite.

Every big bug/issue I wrote changed the way I think&code, to avoid them in the future, examples:

• I don't use negation operator, I'm always explicit if (a == false)
• I use verbose variables after I've spent many hours on a bug like:

//big event loop, within a huge 2D grid game system
//..lots of code
for (x=0; ..; x++) {
    for(y=0;...;y++{
       //lots of code

       //search for a neighbour
       for(x=...;x..){
        }

    }
}//spend many hours to find out why the map was not rendered correctly

I don't remember the specifics, I think it was a shadowing and not declaring var mix of issue, nevertheless now I will try explicitly to avoid i,j,x,y in loops, and ofc I use linters in big projects and static typed languages :))

Forgot to set up a rewind for a segue and wondered why the app dutifully consumed memory no matter how many times the "back" button was tapped. That screen is gone, why are there a dozen copies in memory??!!?

After that adventure I forced myself to learn how to properly use navigation controllers.

Integrating some network code for broadcast traffic, the receiver binds to any active network connections (this is important).

I am receiving every packet twice, without fail.

I go up and down through my transmission code, even adding in timestamp payload to ensure its unique. Check the receive, sure enough, it's decoding the same packet twice, as it appends different timestamps to the decoded payload. So I dive into the code that end.

Turns out I had left the wifi on my laptop, which is also connected to the same network as the hardline.

Whole afternoon pissed up the wall. FMAL.

Boolean errors. Always forgetting to add a ! in validation code.