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

ed, 3 bytes

Note: Most of the answers here are ignoring the trailing newline printed as part of the error message in their count. But I don’t see anything in the question to justify ignoring it, and the author commented that the newline should be included. So unless the question is changed, I’m going to include it.

Code (with trailing newline):

??

Error (with trailing newline):

?

Answer 2

Python 2, 35 bytes

import sys;sys.tracebacklimit=000;a

Gives error:

NameError: name 'a' is not defined

Answer 3

C (modern Linux), 19 bytes

Would've done my famous segfault but totallyhuman stole it.

main(){longjmp(0);}

Output (18 bytes):

Segmentation fault

Answer 4

JavaScript (Firefox), 31 bytes

# This is a comment, right? ...

Throws this error:

SyntaxError: illegal character

Tested in the console of Firefox 54.0.1 on Windows 7.

Answer 5

Python 2, 87 79 bytes

-8 bytes thanks to Zacharý and Erik the Outgolfer.

from __future__ import braces
#i am most surely seriously actually totallyhuman

Try it online!

Error message, 78 bytes:

Assuming the code is stored in a file named a.

  File "a", line 1
    from __future__ import braces
SyntaxError: not a chance

This is actually a nice little Easter egg in Python. :D

Answer 6

Haskell, 13 bytes

main = (main)

Save as t.hs or another one-character name, compile with ghc, and run. Error message (with trailing newline):

t: <<loop>>

Answer 7

><>, 26 bytes

>>>>>>>>>>>>>>>>>>>>>>>>>:

Try it online!

Every error message in Fish is something smells fishy..., so this just moves the pointer right enough times to be longer than that and attempts to duplicate the top of the stack, which is empty at the time.

Answer 8

Taxi, 38 21 bytes

Switch to plan "abc".

Produces:

error: no such label

Try it online!

-17 bytes thanks to Engineer Toast

Tries to switch to "abc", which does not exist. You would have [abc] somewhere.

Answer 9

System V shell, 25 bytes

mount /dev/hda1 /mnt/hda1

Error message (23 bytes):

mount: not a typewriter

"Not a typewriter" or ENOTTY is an error code defined in errno.h on Unix systems. This is used to indicate that an invalid ioctl (input/output control) number was specified in an ioctl system call. On my system, in /usr/include/asm-generic/errno-base.h, I can find this line:

#define ENOTTY          25      /* Not a typewriter */

In Version 6 UNIX and older, I/O was limited to serial-connected terminal devices, such as a teletype (TTY). These were usually managed through the gtty and stty system calls. If one were to try to use either of these system calls on a non-terminal device, ENOTTY was generated.

Nowadays, there is naturally no need to use a teletype. When gtty and stty were replaced with ioctl, ENOTTY was kept. Some systems still display this message; but most say "inappropriate ioctl for device" instead.

Answer 10

JavaScript (Firefox), 21 bytes

(a=null)=>a.charAt(1)

Error (20 bytes): TypeError: a is null

Answer 11

TrumpScript, 30 bytes

We love NATO!
America is great

Error message:

Trump doesn't want to hear it

Answer 12

Javascript (V8), 24 bytes

decodeURIComponent('%');

Error, 23 bytes:

URIError: URI malformed

Tested on Nodejs v6.11.0 and Google Chrome v59.0.3071.115.

Try it online!

Note that TIO expands the error message.

Answer 13

QBasic, 11 bytes

There are two solutions of 11 bytes in QBasic, one of which might be golfed further. The shortest error message QBasic has is overflow, and can be triggered as such:

i%=i%+32677

This throws overflow because the max for an integer (i%) is 32676. I couldn't get the 32677 golfed without QBasic auto-casting this to long...

Another error, at 11 bytes, would be out of data. QBasic has DATA statements that store data in the program, which can later be accessed by READ statements. Issuing more READs than DATAs causes the error:

READ a$ '--

Note that the statement is padded with a comment to get it up to the length of the error message. Yes, I have an error message with a shorter program, and a program with a shorter error message ...

Answer 14

Vyxal, 309 bytes

In this answer, I coded it so that the program errors when executed․
Also, according to code-golf statistics, only a small percentage of people who view my answers actually upvote․ 
So if you enjoy this answer, please consider upvoting - it's free, and you can change your mind at any time․ 
Enjoy the answer․

I request that you imagine Epic Dawn by Bobby Cole is playing while reading this answer.

The Error

Traceback (most recent call last):
  File "C:\Users\61419\Desktop\Vyxal\Vyxal.py", line 867, in <module>
    exec(line)
  File "<string>", line 4, in <module>
  File "C:\Users\61419\Desktop\Vyxal\Vyxal.py", line 592, in VY_int
    return int(item, base)
ValueError: invalid literal for int() with base 10: ''

Explained

This fails immediately on the first instruction it sees: I. It tries to convert the empty input to base 10 (which is impossible)

Answer 15

C (Modern Linux), 19 bytes

I suggested this in chat, but nobody took the oppurtunity. :P Credit to MD XF's hilarious answer.

main(){puts('s');;}

Error message, 18 bytes

Segmentation fault

Answer 16

Commodore 64 Basic, 15 bytes

?SYNTAX   ERROR

Produces

?SYNTAX  ERROR

(Note two spaces in the error message, where the program has three)

?SYNTAX ERROR is tied with ?VERIFY ERROR as the third-shortest error message that C64 Basic can produce, and the shortest that can be reliably triggered by code (the shortest message, BREAK IN 1, requires user interaction, while ?LOAD ERROR requires a defective tape or floppy disk, and ?VERIFY ERROR requires the presence of a floppy or tape containing a file that doesn't match the program in RAM).

Answer 17

PowerShell, 215 189 bytes

[]
111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

Try it online!

So, PowerShell has ... verbose ... error messages. Additionally, most non-syntax error messages are Runtime Exceptions, meaning that they're non-fatal, which reduces this problem to needing to find a short parsing error.

I think this is one of the shortest, if not the shortest, @TessellatingHeckler has demonstrated this is the shortest parsing error, and it still weighs in at 188 bytes just for the error message. So we basically need to append enough 1s to reach 189 bytes of "code."

Running this locally on c:\a.ps1 for example, will cut down on the byte count by a handful as it's just a shorter file path, but then it's not available on TIO.

Produces error:

At /tmp/home/.code.tio.ps1:1 char:2
+ []
+  ~
Missing type name after '['.
    + CategoryInfo          : ParserError: (:) [], ParseException
    + FullyQualifiedErrorId : MissingTypename

Answer 18

Ruby (33 32 bytes)

32 bytes

&
#abcdefghijklmnopqrstuvwxyz12

Throws the error (assuming in a file named "a"):

31 bytes

a:1: syntax error, unexpected &

Edit: Shaved a byte off by using & instead of << thanks to Eric, who also came up with an even shorter Ruby solution: http://codegolf.stackexchange.com/a/135087/65905

Answer 19

R, 29 28 bytes

-1 byte thanks to JarkoDubbeldam

a #abcdefghijklmnopqrstuvwxy

Throws the error Error: object 'a' not foundwhich is 27 bytes.

Try it online!

Answer 20

Brainf**k, 17 bytes, this interpreter

+++++++++++++++<<

Brainf**k is such a simple language that almost every interpreter has a different error message. This one uses Memory Error: -1 for when the pointer is moved to the left too much and you attempt another operation

Answer 21

Common Lisp, 20 bytes

(/ 1 0))))))))))))))

Try it online!

Error Message

/: division by zero

Answer 22

TryAPL, 11 bytes

Code (11):

'abcdefghij

Error (10):

open quote

Answer 23

Perl 5, 11 bytes

Since I'm not clear on whether my other answer obeys the challenge rules, here's another alternative.

#line 0
die

Error output:

Died.

With an ending newline, for 6 bytes.

Try it online!

For some reason the Perl interpreter internal function Perl_mess_sv contains:

if (CopLINE(cop))
    Perl_sv_catpvf(aTHX_ sv, " at %s line %" IVdf,
                    OutCopFILE(cop), (IV)CopLINE(cop));

where CopLINE(cop) gets the current code context's line number. So if that line number happens to evaluate to zero, Perl skips adding the usual " at <filename> line <n>" to the error message.

Answer 24

ZX Spectrum Basic, 9 bytes

RUN USR 8

produces:

Explanation:

I am (exceptionally) counting ASCII representation of the program for length purposes, including the end of line (it's not really important, since we could always pad a shorter program with spaces).

Usually, ZX Spectrum error messages are longer and more helpful than this - the ROM routine at 0x0008 expects error code following the machine code call to RST 8., and fetches some random (deterministic) byte from the ROM, which produces this nonsensical error message M. 5 is the error number, , is added by the error printing routine and 0:1 is the line:command position of the error.

Answer 25

ArnoldC, 150 bytes

IT'S SHOWTIME
HEY CHRISTMAS TREE b
YOU SET US UP 0
GET TO THE CHOPPER b
HERE IS MY INVITATION b
HE HAD TO SPLIT 0
ENOUGH TALK
YOU HAVE BEEN TERMINATED

Try it online!

Error is 94 bytes (including trailing newline):

Exception in thread "main" java.lang.ArithmeticException: / by zero
    at code.main(Hello.java)

---

Preserved because I think this is more funny - spoiler: it was those dang teenage pranksters.

ArnoldC, 280 bytes

IT'S SHOWTIME
HEY CHRISTMAS TREE BRBDoorBetterNotBeThosePeskyTeenagePranksters
YOU SET US UP 0
GET YOUR ASS TO MARS BRBDoorBetterNotBeThosePeskyTeenagePranksters
DO IT NOW
I WANT TO ASK YOU A BUNCH OF QUESTIONS AND I WANT TO HAVE THEM ANSWERED IMMEDIATELY
YOU HAVE BEEN TERMINATED

Pseudocode:

start program
new variable
set to 0
set new variable to output from function
call function
take input
end program

Try it online!

Generates a "no input" error. (Almost all other errors in ArnoldC include a large piece of boilerplate):

279 bytes (including trailing newline):

Exception in thread "main" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Scanner.java:862)
    at java.util.Scanner.next(Scanner.java:1485)
    at java.util.Scanner.nextInt(Scanner.java:2117)
    at java.util.Scanner.nextInt(Scanner.java:2076)
    at code.main(Hello.java)

Answer 26

Perl 5, 5 bytes

die$/

Outputs a newline, for one byte.

Try it online!

Answer 27

GW-Basic, 9 bytes

Enter:

?&H100000

This will yield the following error message:

Overflow

I believe this is the shortest error message in GW-Basic. The reason I used a hexadecimal constant is that while GW-Basic doesn't support long integers, it does support single and double(!) precision floating point numbers.

Answer 28

Whitespace (on TIO), 34 bytes

 
Nope, it's not valid Whitespace!

Try it online.

All characters that aren't a space, tab, or newline are ignore in Whitespace. So this program is actually SNSSS (where S is space, and N is newline). The first three (SNS) is the command to duplicate the value at the top of the stack. Since the stack is still empty, it gives the error:

wspace: user error (Can't do Dup)

I tried other errors, but this seems to be the shortest. Most errors where it tries to use a value on the stack which isn't present are similar, but longer. Here is a list of all possible errors (I could find) on TIO (for the first one it requires a character input, which it tries to read and print as number, so I've excluded that one - Try it online.):

wspace: Prelude.read: no parse
wspace: user error (Can't do Dup)
wspace: user error (Can't do Swap)
wspace: Prelude.!!: index too large
wspace: user error (Can't do Store)
wspace: user error (Can't do Return)
wspace: user error (Can't do Discard)
wspace: user error (Can't do Slide 0)
wspace: user error (Can't do ReadNum)
wspace: user error (Can't do Retrieve)
wspace: user error (Can't do ReadChar)
wspace: <stdin>: hGetChar: end of file
wspace: <stdin>: hGetLine: end of file
wspace: user error (Can't do OutputNum)
wspace: Prelude.chr: bad argument: (-1)
wspace: user error (Can't do Infix Plus)
wspace: user error (Can't do OutputChar)
wspace: user error (Undefined label ( ))
wspace: user error (Can't do Infix Minus)
wspace: user error (Can't do Infix Times)
wspace: user error (Can't do If Zero " ")
wspace: user error (Can't do Infix Divide)
wspace: user error (Can't do Infix Modulo)
wspace: user error (Can't do If Negative " ")
wspace: Input.hs:(108,5)-(109,51): Non-exhaustive patterns in function parseNum'
wspace: Unrecognised input\nCallStack (from HasCallStack):\n  error, called at Input.hs:103:11 in main:Input
wspace: Stack space overflow: current size 33624 bytes.\nwspace: Relink with -rtsopts and use `+RTS -Ksize -RTS' to increase it.

---

NOTE: Whitespace compilers have their own implementations for error messages. All these errors above are on TIO. If I use the online Whitespace compiler vii5ard instead, and use the same program at the top, it will give this error instead:

ERROR: Runtime Error: Stack underflow

So using the vii5ard online Whitespace compiler I could lower my byte-score to:

Whitespace (on vii5ard), 15 bytes

Unexpected EOF!

Which is the 'program' S (a single space), resulting in the error:

Unexpected EOF

(Which would result in wspace: Unrecognised input\nCallStack (from HasCallStack):\n error, called at Input.hs:103:11 in main:Input on TIO).

Answer 29

05AB1E, 410 411 bytes

One plus one is two, two plus two is four.
And now, some random character spam just because I can.
3...
2...
1...
GO!

ooi1u4`o1i2)I#1n[09i43u`1@#~!@#{10239`]ι@(~!)2ioausioe7u12o3iu71p3123`71i2`8127l5ruy;3948'p3298rv9pe8huep'r8i19o`8u'3pie8uiouI!^23uT7T17I3YJH~:L'I`YU2O123;121@

That should be about it, it errored. Guess that's what happens when you spam. Bye for now!


upvote if you liked my creativity


:)

Try it online!

One plus one i...]ι...  # trimmed program
One plus one            # push empty string ("") twice
             i          # if top of stack is truthy...
              ...       # execute (trimmed) code (this is unreachable)
                 ]      # exit all opened statements
                  ι     # not exactly sure what this function does, but part of it forcefully converts top of stack to an integer (without error handling), therefore erroring
                   ...  # unreachable code as program has quit from the fatal error

Error, 410 bytes

** (RuntimeError) Could not convert  to integer.
    (osabie) lib/interp/functions.ex:101: Interp.Functions.to_integer!/1
    (osabie) lib/interp/commands/special_interp.ex:113: Interp.SpecialInterp.interp_step/3
    (osabie) lib/interp/interpreter.ex:127: Interp.Interpretr.interp/3
    (osabie) lib/osabie.ex:62: Osabie.CLI.main/1
    (elixir) lib/kernel/cli.ex:105: anonymous fn/3 in Kernel.CLI.exec_fun/2

Answer 30

Javascript (Firefox), 29 27 bytes

new Date('-').toISOString()

throws RangeError: invalid date which is 24 bytes. Tested on Firefox 54.0.1 on Windows 10.