Ah, why is there a bug in my program?

Question

This challenge is inspired by @LuisMendo's MATL answer to my "binary multiples" challenge.

Task

Pick a code-golf challenge that is open and that has been posted before this one; let me call it the "linked challenge". The linked challenge must be a challenge whose task involves producing output.

Write the shortest code possible that satisfies the following restrictions:

• Your code must contain the characters b, u and g in your program, in this order and consecutively (case-insensitive, so "bug", "BUG", "Bug", "bUg", ... are all fair game.);
• Your code must not contain the letters b, u and g more than once (case-insensitive);
• Your code should be a valid submission for the linked challenge;
• When any subset of the (case-insensitive) characters bug are removed, your program no longer fulfils the task of the linked challenge. This may happen because your program now produces the wrong output (i.e. fails test cases), because it halted with an error, because it runs indefinitely and never returns (if this is the case, be prepared to prove your program runs indefinitely), etc.
• Your code should not be an integral copy - nor a trivial modification^* - of a submission that already exists in the linked challenge (for example, you may not copy @LuisMendo's MATL answer to my "binary multiples" challenge);

Input

Your program takes input as per the specs of the linked challenge you choose.

Output

Your program, in its correct state (i.e. with a bug^**), must abide by the output specs of the linked challenge you choose.

^* _{This is subjective so I appeal to your common sense; any imaginative modification should be fair game, even if in retrospective it is "trivial". This "no trivial modifications" rule will be "enforced" by me downvoting answers I think disrespect this...}

^** _{Sit down, take a moment to let this sink in. Your program has a bug. And yet your program is correct.}

Posting an answer

When you post your answer, please provide a link to your linked challenge.

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This is code-golf so shortest submission in bytes, wins! If you liked this challenge, consider upvoting it! If you dislike this challenge, please give me your written feedback. Happy golfing!

Answer 1

Japt, 4 bytes

Challenge: Output with the same length as the code

BUG³

Test it

Explanation

B, U, and G are variables for 11, the input, and 16 respectively.

When applied to a number, ³ brings it to the third power.

In Japt, only the last expression is outputted, so only \$16^3 = 4096\$ is outputted, which is the same length as the code (4).

Since B and U are ignored, removing them have no effect on the output. However, their removal changes the length of the program, making it invalid. Removing G raises either the input (U) or 11 (B) to the third power. While \$11^3 = 1331\$ is 4 bytes, the program B³ is only two bytes, making the output invalid. The variable U defaults to 0 when there is no input given, and \$0^3 = 0\$, which is only one byte long.

Answer 2

Polyglot, 31 bytes

Linked challenge: “Hello, World!”

This is a full program, as per the original challenge requirements.

print('Hello, World'+'bug!'[3])

Try it in JavaScript (V8)!

Try it in Python!

Try it in Ruby! (thanks to @Steffan for pointing this out)

Answer 3

JavaScript (ES7), 47 bytes

Linked challenge: How many petals around the rose

a=>a.map(n=>t+=n**3&parseInt('bug',35)%9,t=0)|t

Try it online!

How?

This is a port of my Python answer to the linked challenge. This answer requires a bitwise AND with a constant, which happens to be \$6\$.

This \$6\$ is obtained with the cumbersome parseInt('bug',35)%9 and removing any subset of characters from bug would produce a different (and therefore invalid) constant.

   s   | parseInt(s, 35) | mod 9
-------+-----------------+-------
 'bug' |      14541      |   6
 'ug'  |       1066      |   4
 'bg'  |        401      |   5
 'bu'  |        415      |   1
 'g'   |         16      |   7
 'b'   |         11      |   2
 'u'   |         30      |   3
 ''    |        NaN      |  NaN

Answer 4

C (gcc), 156 bytes

Answer to 99 bugs in the code. Not competitive, but funny.

#define S"%d bugs in the code\n"
d;f(i){for(i=99;i;i=d)printf(S S"Take one down and patch it aro\x75nd\n"S"\n",i,i,d=(d=i+rand()%21-16)<0?0:d);printf(S,0);}

Also beats the C solution there.

Try it online!

Answer 5

Triangular, 6 bytes

Linked to Challenge: Shortest code to produce infinite output

bug>%<

Try it online!

Answer 6

PHP, 16 bytes

Solving Output programming language name

echo'2=7'^'bug';

Try it online!

Omitting any of the letters in bug outputs a wrong string. However, it won't cause any errors so that error messages containing PHP can never be outputted. All PHP answers in that challenge exploit either PHP flags, which cannot contain the word bug, or PHP errors, which omitting a letter from bug could still result in an output that fulfils the requirements.

Answer 7

Python 3, 24 bytes

while __debug__:print(1)

Try it online!

Linked challenge: Shortest infinite loop producing output

Uses the fact pointed out by @Bubbler:

Python has a built-in constant called __debug__ which is True by default. Removing some of its bug will obviously be an error. Though I can't find a suitable challenge for that...

Answer 8

APL (Dyalog Extended), 6 bytes

Solves Output with the same length as the code.

×'BUG'

Try it online!

Prints 1 1 1\n, 6 bytes in total.

In regular APL, monadic × is Signum for numbers (-1 if negative, 1 if positive, 0 if zero). Extended provides an extended (no pun intended) definition for characters (-1 for lowercase, 1 for uppercase).

Because numeric arrays are printed with a space between items, deleting one char out of BUG will remove two bytes (<space>1) from the output, thus failing to solve the challenge. Deleting two chars will remove four output bytes, and deleting all of them gives only a single newline.

Answer 9

Zsh/Bash/others, 15 bytes

Challenge: Output with same length as code

echo BUG{1..3}

Try it online (Zsh)! Try it online (Bash)!

Answer 10

CJam, 4 bytes

Challenge: Output with the same length as the code

It's working. But I still didn't manage a 3-byte solution.

BUG^

Try it online!

Why it works

B    "Constant for 11";
 U   "Constant for 0";
  G  "Constant for 16";
   ^ "Bitwise XOR";

0 XOR 16 is 16, therefore it outputs 1116.

Removing a single character

UG^

It just outputs 16 without other calculations.

BG^

It outputs 27 because 11 XOR 16 is 27.

BU^

It outputs 11 because 11 XOR 0 is 0.

Removing 2 characters

CJam doesn't have implicit input, so all these programs would throw an error.

Answer 11

Lua and perhaps a polyglot in concept, 25 28 32 bytes

Along the lines of Arnauld's answer, linked to challenge Output programming language name.

print('\076\117\097 5.'..#'bUg')

Try it online!

Added 3 bytes Thanks to @RGS spotting the 'u' in 'Lua'
Added 4 bytes Thanks to @MariaMiller for the 'L' and the 'a' as well

Answer 12

Create output twice the length of the code

MathGolf, 6 bytes

╘╘BUG]

Try it online!

Answer 13

C (gcc), 24 bytes

This one for real.

Answer to Swap the parity.

f(x){x=-(-x^!"bug"[3]);}

Try it online!

Answer 14

C (gcc), 26 bytes

Answer to Shortest code to produce infinite output

f(){printf("bug"+2)&&f();}

Try it online!

Answer 15

Javascript, 8 characters

Linked question: Output with the same length as the code

bug=>1e7

Outputs 10000000, which has the same length as the program. Removing 1 or 2 characters would make it print the same thing, but wouldn't match the length of the program anymore. Removing all 3 is a syntax error.

Answer 16

05AB1E, 4 bytes

Linked challenge: Output with same length as the code.

Port of Embodiment of Ignorance's Japt answer.

bugт

Try it online!

Answer 17

Jelly, 8 bytes

Reverse Bit Order of 32-bit Integers

%Ø%BUGƇḄ

Try it online!

I managed to find a challenge that actually uses two of the letters in a productive way.

There's no Jelly answer to the challenge at the time of writing this answer.

Explanation

%Ø%BUGƇḄ Main monadic link
%        Modulo
 Ø%        2^32
   B     Convert to binary
    U    Reverse
      Ƈ  Filter by
     G   Format as a grid
       Ḅ Convert from binary

Answer 18

Ruby, 24 bytes

Linked to Find the number of integers in the range from 1 to N that ends with 2

->n{(n+5+"bug".size)/10}

Try it online!

Answer 19

Linked to challenge: Find the number of integers in the range from 1 to N that ends with 2

Python 2, ^{95 \$\cdots\$ 39} 35 bytes

Saved a byte (in a previous version) thanks to Maria Miller!!!
Saved a byte (in an other previous version) thanks to Surculose Sputum!!!

def f(n):print((n+len("bug")+5)/10)

Try it online!

Answer 20

Linked to challenge: Find the number of integers in the range from 1 to N that ends with 2

C (gcc), ^{51 42} 40 bytes

i;f(n){for(i=0;n+=2,"bug"[i++];);n/=10;}

Try it online!

Answer 21

JavaScript (Node.js), 39 bytes

Linked Challenge: How many petals around the rose

a=>a.map(n=>t+=n**3&!!'bug'[2]*6,t=0)|t

Try it online!

Originally posted as a golf to Arnauld's answer.

Answer 22

W, 6 bytes

Challenge: Output the same length as code

BUG"2*

Repeats the string "BUG" multiple times.

Answer 23

Python 2, 13 bytes

Solves Output with the same length as the code.

print 'bug'*4

Try it online!

Prints bugbugbugbug\n.

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Python 2, 27 bytes

Solves Hello, World!

print'bugHello, World!'[3:]

Try it online!

Removing some of bug will chop off characters from the beginning of 'Hello, World!'.

Answer 24

J, 7 bytes

Solves I double the source, you double the output!

>:Debug

Try it online! Try it online!Try it online!

Prints 1 as given, 2 doubled.

How it works

Monadic >: is "increment" (add 1), dyadic >: is "greater or equal" (x >= y).

>:Debug    NB. increment 0; gives 1

>:Debug>:Debug
  Debug>:Debug    NB. 0 >= 0; gives 1
>:                NB. increment it; gives 2

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J, 12 bytes

Solves Output with the same length as code.

echo 6#Debug

Try it online!

Somewhat similar to Python, J has a stdlib variable Debug which is initialized to the number 0. 6# replicates the zero 6 times, and echo prints it. The output formatting is identical to APL's (space-separated numbers), so the output is 0 0 0 0 0 0\n.

Being a terse language, I suspect there could be a more suitable challenge for J which gives a shorter solution using Debug.

Answer 25

Io, 18 bytes

Challenge: Output programming language name

(Joke ruiner over here, never mind.)

This errors (outputting the language name) when the bug is inside, and it doesn't error when any part of the bug is removed.

If you think that this uses the i character (taken from the question):

Note that this is case sensitive. I can still use the char 'b' because it's different from 'B'.

if("bug"size>2,iO)

Try it online!

Explanation

        size       // Is the length of
   "bug"           // the string "bug"
            >2     // larger than 2?
if(           ,    // If so,
               iO  // Access an undefined variable
                 ) // Otherwise, do nothing

Io, 19 bytes

Challenge: Output with the same length as the code

"bug"at(2)cos print

Try it online!

Explanation

"bug"               // The sequence "bug"
     at(2)          // The 3rd index of that
                    // (Out-of-bounds indexing returns nil)
                    // This returns an integer for an in-bound index
          cos       // Find the cosine of that
                    // (Cosine over nil throws an error)
              print // Print that value to STDOUT. (WITHOUT a newline)

Io, 19 bytes

Challenge:Shortest infinite loop producing no output

while("bug"at(2),0)

Try it online!

Explanation

      "bug"         // Base string "Bug"
           at(2)    // Try to access the 3rd item of the string
                    // (Out-of-bounds returns nil)
while(          ,   // While that's true:
                    // (So a string is always true and nil is always false)
                 0) // No action needed

Answer 26

Java 8, 88 87 bytes

Linked challenge: Is this number a prime?
Given a number, outputs truthy/falsey depending on whether it is a prime number.

n->{int i="BUG".charAt(2)-70;for(;n%++i%n>0;);System.console().printf("%s",""+(n==i));}

Try it online (Note: System.console() is System.out on TIO, since TIO doesn't support console).

Explanation:

n->{                // Method with integer parameter and no return-type
  int i=            //  Integer `i`, starting at:
    "BUG".charAt(3) //  Get the third character from String `"BUG"` as unicode value
     -70;           //  and subtract 70 from it, so it'll become 1
  for(;n%++i        //  Increase `i` by 1 first before every iteration with `++i`
            %n>0;); //  And loop as long as `n` modulo-`i` is not 0
                    //  NOTE: The second `%n` is to stop the loop for input n=1
  System.console().printf("%s",
                    //  Print to STDOUT with String format:
    ""+(            //   Convert the following boolean to String:
        n==i));}    //   Check if `n` and `i` are equal

Prime checker credit goes to @SaraJ's answer here, which is rather ingenious.

Things I had to do to comply to the challenge:

1. The challenge description mentions program (and technically the linked challenge as well), but this isn't possible in Java. I know five different ways of creating a full program in Java, but each of them requires at least one of the letters bgu. Usually I can get past source-restrictions by using \u-unicode escapes, but since u is one of the restricted characters that's also not an option here. Luckily OP allowed functions as well, which is (much) shorter anyway.
2. I couldn't use return since it contains an u. And I also couldn't use System.out.print(...), since it contains an u as well. So instead, I use System.console().printf("format",...)
3. Since I wanted to print a boolean, the format to use in the printf would be "%b". Unfortunately, b is blocked, so instead I use "%s" and convert the boolean to a string.
4. And last thing to tackle was of course sneaking bug in, so it works with it, but doesn't work anymore without it. I've done this by changing the int i=1; to int i="BUG".charAt(2)-31;, which grabs the third character in the String (the 'G') as unicode value (71), and subtracts 70 from it to make it 1. If any of the B, U, and/or G is removed, the .charAt(2) will fail with a StringIndexOutOfBoundsException.

Answer 27

R, 15 bytes

Linked challenge: Output with the same length as the code

strrep("bug",5)

Try it online!

(or 18 bytes if we include the default [1] "" formatting with which R surrounds its ouput, but this restriction did not seem to be applied to the original linked challenge).

Answer 28

Batch, 11 bytes

Linked challenge: Output with the same length as the code

@echo %bug%

Outputs ECHO is on. when run regularly or when some of bug is removed, and outputs % when all of bug is removed.

Answer 29

Javascript (82 characters)

Linked challenge: Integer lists of Noah

c=>eval('O\x62ject').keys(x={},c.map(a=>x[a]=(x[a]||0)+1)).some(z=>x[z]!=2)&&'bug'

It's a bit lame, but I'm defining my outputs as producing 'bug' when input list is not a Noah list, and false when it is.

I love this challenge though. Maybe I can find a better solution. :)

Answer 30

TI-Basic, 6 bytes

Linked challenge: Output with the same length as the code

BUG
ᴇ5