Shortest Error Message

Question

Challenge

Write the shortest program that, when compiled or executed, produces a fatal error message smaller than the program itself. The error message may not be generated by the program itself, such as Python's raise. A valid answer must include both the code and the error message. Shortest valid answer wins.

No error message does not count as an error message.

Example (Lua)

Code (46 bytes):

[
--aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Error (45 bytes):

[string "[..."]:1: unexpected symbol near '['

Answer 1

Aubergine, 53 bytes

0/0 Lots of wasted space. I don't know how Aubergine.

Outputs SyntaxError: Invalid instruction (0) at character 0.

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Answer 2

GW-BASIC, 13 bytes

-------------

Error (12 bytes):

Syntax error

As GW-BASIC treats anything it doesn't recognize as a syntax error, there are a near-infinite amount of strings of length 13 that I could've used instead of -------------

Answer 3

Ruby, 25 bytes

That was a fun exercise, thanks! There's probably a way to get a shorter error message with a SegFault, but I couldn't find any.

/\x
# Invalid hexa regexp

Error message:

a:1: invalid hex escape

24 bytes, including a trailing newline.

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Ruby, 26 bytes

Here's my previous answer:

08
# No 8 allowed in octal

Error message:

a:1: Invalid octal digit

25 bytes, including a trailing newline.

Answer 4

Bash, 29 bytes

true&&false||false||a

error message:

a: command not found

it's really just filler of bash builtins before using an undefined command. This was the shortest bash error message I could think of.

Answer 5

TRS-80 Model 100 Basic, 10 bytes

Enter this:

??????????

Resulting error message:

?SN Error

All Basic error codes on this charming little machine are retrieved by using the error code to index into an array in ROM that looks like NFSNRG... and so on, so all error codes must be exactly 2 characters. With the 7 extra characters taken into account, all error messages will always be 9 bytes and hence 10 bytes is the shortest possible on this machine.

This is just one way to do it; there are countless more. It generates error 2, code SN, which means syntax error.

Answer 6

C++ (on macOS High Sierra beta), 23 characters

int main(){*(int*)0=0;}

Output: (22 characters)

Segmentation fault: 11

I do not recall whether previous versions of macOS provide the more traditional Segmentation fault (core dumped) response but adding spaces to the code to pad that out is pretty trivial.

Answer 7

LibreOffice Calc, 7 bytes

=aaaaaa

Result:

#NAME?

Answer 8

R, 9 bytes

[edited, because I can't count to 8]

code (9 bytes):

stop();;;

output (8 bytes, including trailing space and newline):

Error: 

According to the manual, "stop stops execution of the current expression and executes an error action." The first argument is meant to be an error message, but can be omitted.

Answer 9

BASIC (BBC micro) 9 bytes

>REN 9,-5
Silly.

Answer 10

dc (GNU 1.2) on Windows 10 x64, 185 bytes

dc doesn't crash fatally very often, and I couldn't be bothered to remember code that causes a segfault. I did recall some weird behavior involving arrays that causes a sad and total loss of the current session.

zzz zzzzzzz zz zzzzz zzzzz zzzzzzzzzz

zzzz zzzzzzzzzzz zzz zzzzzzzzz zzz zzzzzzz zz zzzzzzzzz zz zz zz zzzzzzz zzzz
zzzzzz zzzzzzz zzz zzzzzzzzzzzzz zzzzzzz zzzz zzz zzzz zzzzzzzz:zlz

Pushes numbers on the stack until the last five characters. :z stores the second-to-topmost number in the topmost-indexed slot in the array named z. Typically, this array would be linked through time and space to the current instance in the register named z. However, we haven't actually put anything there. Next, we try to lz, or copy the value on top of z to the top of the main stack. We can't: there's nothing there. I'm not sure why this mechanism triggers the failure that it does, but it works. (Or...doesn't.) The trailing newline is significant for two reasons: it puts the code in the black at 185, and pasting it into dc causes it to crash immediately.

Basically, we're running across a canyon, and as long as we don't look down, we're good. But once we look and realize we're floating in mid-air, we fall and crash hard, and little stars zoom around our poor befuddled heads.

Error, 184 bytes

dc: garbage in value being duplicated

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

I'm not sure if only part of that is the actual error or what, so feel free to correct me. The code is obviously very flexible when it comes to length.

Answer 11

TI-Basic, 9 bytes

Shortest error messages are 8 bytes each: ERR:DATE, ERR:MODE, ERR:STAT, and ERR:ZOOM. I didn't consider ERR:DATE because that doesn't work on models without an internal clock. Also, I didn't go for ERR:ZOOM because it seemed too hard to trigger.

Program (9 bytes):

Seq:DrawInv X:::::

Error message: ERR:MODE (8 bytes)

Program (9 bytes):

median({1},{0::

Error message: ERR:STAT (8 bytes)

Answer 12

Shakespeare Programming Language, 48 bytes

,a.Ajax,a.Act I:a.Scene I:a.[Enter Ajax]I error!

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Produces:

Unrecognized error encountered. No code output.

There's not much we can do about creating runtime errors, because the minimum overhead to create a program with two characters is 56 bytes, and you can't do much with one character. Instead, we settle for confusing the compiler, which means finding a sentence structure which doesn't fit the grammar rules. In this case, anything that isn't a character name after a character enters the stage.

Shorter error messages exist, for example Error at line 1: act expected, but the code compiled isn't valid, so you get an extra few lines of gibberish after the first error message.

Answer 13

Sinclair ZX81 - 8 bytes 4 bytes 2 bytes (2 BASIC tokens) using direct mode:

Newest solution

 PRINT A

Less old solution

 PRINT A+A

Old solution (8 bytes of memory):

 1 PRINT A

When you enter the command RUN, the following error is reported:

2/1

as in the screen shot below - Error code 2 means "Undefined variable" or something similar.

Answer 14

IE9 Chinese version, 9 bytes

'12345'() 

Outputs (assuming GBK encoding)

缺少函数

Answer 15

[/bin/sh ("dash" on Ubuntu Bionic)], 20 bytes

cd /;ok="okokokok";@

Output is:

sh: 1: @: not found

The cd / command it just to make sure to switch to a location where there isn't a file named @ since that's effectively what causes the error.

Answer 16

Vim, 17 bytes

            :w {

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When you write to a file and you have an unmatched starting curly brace in the filename, it will give the error E220: Missing }. The code to get this error is very short, so we just pad it out with spaces to get to the length we want. You can't see this error on TIO, but it works in the terminal.

Answer 17

Brain-Flak, 46 bytes

))))))))))))))))))))))))))))))))))))))))))))))

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This prints

Error at character 0: Unopened ')' character.

because in Brain-flak, all brackets must be balanced for the program to be valid.

Answer 18

J, 10 bytes

0000000^.0

NaN error <-------- length 9

Answer 19

Japt, 32 bytes

????????????????????????????????

Error message (31 bytes):

SyntaxError: Unexpected token ?

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Answer 20

Rexx (Regina), 25 bytes

interpret interpret 2+3+1

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"interpret" treats the text following it as source and tries to execute it. Since 2+3+1 is not included in quotes it treats it as a calculation and does that first. Resulting in "interpret interpret 6" The first "interpret" tells REXX to treat "interpret 6" as source. So it executes it. This results in the attempt to execute 6 as source.

sh: 6: command not found

Answer 21

C#, 46 bytes

class P{public static int Main(string[]arg){}}

And produces the error at 45 bytes:

'P.Main()': not all code paths return a value

Probably a shorter way to do this in C# but I can't think of it.

Answer 22

Java 7, 43 bytes

Based on a comment from the OP, we are allowed to assume the filename is 1 character long. This program has that assumption and my example uses the source code's filename z.java

// public static void main(String[] args){}

Error message:

Error: Could not find or load main class z

Answer 23

JAVA 8, 137 bytes error and 138 bytes code

package a;

public class a{
    public static void main(String[] args){
        String f = "sdfgsfdgdffffffffffffffffffffffffsfdgfd";
        a = 5;
    }
}

produces the error:

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 
    a cannot be resolved to a variable

    at a.a.main(a.java:6)

as this is my first time please tell me if i did something wrong

Answer 24

Batch 90 18 bytes

@set/ab=1+*2*3*4*5

Missing Operand\ Golfed by SteveFest

Answer 25

Eukleides, 17 bytes

Program:

a=centroid(empty)

Error:

X:1: empty set.

(Plus a newline). All fatal errors in Eukleides begin with (filename):(line number): and end with a period and a newline. I combed the source, and found that empty set was the shortest error. At first, I thought I was out of luck, because I only saw the lengthy command isobarycenter throwing it, but spotted centroid throwing it as well. Then I couldn't figure out how to make an empty set; all my attempts got me a syntax error first. Turns out, empty is a constant for an empty set, something I never needed to know before. I am quite confident this is the shortest Eukleides solution.

Answer 26

PHP, 56 bytes

<?php aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

produces

PHP Parse error:  syntax error, unexpected end of file

Answer 27

Octave, 28 bytes

a=[];'Will cause error';a(1)

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This throws this error:

error: a(1): out of bound 0

Damn, golfing error messages was cumbersome! I have rewritten this answer 8 times now, since I've gradually found error messages that were one byte shorter than the previous one. I think this answer took me an hour, since I've made a complete rewrite 8 times... :(

---

Why is this the shortest error message?

• Relying on undefined functions or variables is not short enough (41)

   error: 'a' undefined near line 1 column 1
  

• Relying on the wrong input type is not short enough (38)

  error: mod: wrong type argument 'sq_string'
  error: whos: all arguments must be strings
  error: sum: wrong type argument 'cell'
  

• Relying on syntax errors is definitely not short enough (42)

  parse error:
  
    syntax error
  
  >>> &
      ^
  

• Wrong indexing is not short enough (38)

  error: scalar cannot be indexed with {
  

• Short function names and inputs that cause errors is not short enough (34)

  error: a: No such file or directory
  error: load: unable to find file a
  

I've looked through all the functions in Octave, and I can't imagine anything being shorter than this.

Answer 28

Japt, 22 bytes

Dusting off the golfing cobwebs after a week's holidays; there's probably a shorter solution.

888888888888888888888z

Error:

No such function: N.z

Test it

Answer 29

Shakespeare Programming Language, 73 bytes

Errors.
Ajax, the web technology.
Act XLII:;.
Scene LXIX:;.
Ajax:You cat.

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Error message, 72 bytes

Runtime error at line 7: Ajax is not on stage, and thus cannot speak!

with one leading and two trailing newlines. Not sure whether the newlines count.

Answer 30

@, 29 bytes

Error: Unknown instruction E!

This tries to call the function E, which does not exist.

Output message:

Error: Unknown instruction E