Make an error quine!

Question

Your challenge: write a "program", for a language of your choice, that causes the compiler/interpreter/runtime to produce error output when compiling/running your program which is identical to your program's source code.

Rules:

• Your program may be specific to a particular version or implementation of your language's compiler/interpreter/runtime environment. If so, please specify the particulars.
• Only standard compiler/interpreter/runtime options are permitted. You cannot pass some weird flag to your compiler to get a specific result.
• The program does not need to be syntactically or semantically valid, but I may give a bounty to the best syntactically valid submission.
• The program must not produce any output of its own (e.g. by calling a print or output function). All output generated upon attempting to compile/run the program must originate from the compiler/interpreter/runtime.
• The complete output of the compiler/interpreter/runtime must be exactly identical to your program source code.
• The compiler/interpreter/runtime must generate at least one error message when invoked with your program.

This is a popularity contest. Most creative answer, as determined by upvotes, wins. If you can give a good case for using a standard loophole, you may do so.

Answer 1

GW-BASIC (least: 12 bytes)

Syntax error

Inspired by the Commodore 64 BASIC answer. Knocked off 2 bytes because IBM and DOS are better than Commodore :P You can download an emulator for GW-BASIC.

NEXT without FOR

Since GW-BASIC is a line-based language, it only evaluates the first instruction after a newline or colon :. Therefore, it reads NEXT and automatically fails it didn't read a FOR.

Apple ][ BASIC (13 bytes)

?SYNTAX ERROR

Woo, 1 less byte than the Commodore answer because the old Apples could beat a Commodore anyday :P

QBasic (43 bytes)

Parse failed: Syntax error at 1:1: Token(:)

Might be cheating because it only works on the first line.

Applesoft BASIC (69 bytes)

ParseError: Syntax error: Expected line number or separator in line 0

Also only works on the first line...

Answer 2

sed

By using this general approach, I have converged on several sed error quines. This may not work in your sed, in which case, you're using the wrong sed, and therefore would you please acquire necessary, error-quining sed.

Try it online! This version works in TIO, and probably not anywhere else. Open the "Debug" panel to see the error.

Where sed is macOS's default sed, and gsed is a GNU sed.

Answer 3

Recursiva, 7 bytes

Error!

Try it online!

Answer 4

VB.Net, 32 Bytes

Create a new, empty project named 'A'. Set the startup object to "Sub Main" (it's a drop-down option). Create a new class called anything. Delete everything from the class and copy/paste the following:

'Sub Main' was not found in 'A'.

This works because a single quote is a comment, so it looks like a blank file :D

Answer 5

K (ngn/k), 2 bytes

'c

Try it online!

'c is the response from the console indicating that the variable c is undefined

Answer 6

MiLambda

ERROR_NOHALT

Try it online!

Seems like a short solution

Answer 7

Turing Machine But Way Worse, 258 bytes

Traceback (most recent call last):
  File "/opt/tmbww/TuringMachineButWayWorse.py", line 16, in <module>
    i[0], i[2], i[3], i[5], i[6] =  int(i[0]), int(i[2]), int(i[3]), int(i[5]), int(i[6])
ValueError: invalid literal for int() with base 10: 'Traceback'

Try it online!

Answer 8

ZSH (macOS), 20 bytes excluding newline

 zsh: bad pattern: ^[

Answer 9

Ly

Error occurred at program index 3, instruction o (zero-indexed, includes comments)
EmptyStackError: cannot pop from an empty stack

Demo (using official compiler)

This program makes use of the o in "Error", the first instruction character in the error message that produces an error. (apparently r does nothing with an empty stack)

When a stack is not empty, o takes the top entry off the selected stack and outputs it as ASCII; EmptyStackError occurs when the selected stack is empty. So when Ly runs into this o, it causes this error, since we haven't given the stack anything yet.

Answer 10

W.Y.A.L.H.E.I.N., 253 bytes

Traceback (most recent call last):
  File "/opt/wyalhein/whenyouaccidentallylose100endorsementsinnationstates.py", line 6, in <module>
    seed = int(contents[0])
ValueError: invalid literal for int() with base 10: 'Traceback (most recent call last):\n'

Try it online!

whenyouaccidentallyloseahundredendorsementsinnationstates expects a seed on the first line, and Traceback (most recent call last): is not a valid number (unless we're talking in base 96, of course, but whenyouaccidentallyloseahundredendorsementsinnationstates doesn't).

Answer 11

Loader (using the official Java interpreter):

These should be run from a module named main in order to produce the exact error messages given here.

This works in the most recent version of the interpreter:

Error: Could not evaluate expression Error (module main, line 1)

Explanation:

expression:statement is a conditional. The interpreter doesn't even syntax check the stuff to the right of the colon (if it did, we'd get a different error message) unless the stuff on the left evaluates to a nonzero value. However, as "Error" is an illegal expression, the interpreter can't evaluate it, exiting the program with this error message.

In some earlier interpreter versions, this would work instead:

Exception in thread "main" java.lang.RuntimeException: Could not evaluate expression Exception in thread "main" java.lang.RuntimeException (module main,line 1)
    at Loader.expr(Loader.java:183)
    at Loader.load(Loader.java:201)
    at Loader.main(Loader.java:249)

Answer 12

ESOPUNK, 38 bytes

Invalid instruction INVALID at line 0.

Answer 13

C (tcc), 42 bytes

.code.tio.c:1: error: declaration expected

Try it online!

Answer 14

MS SQL (Server version 2012), 64 bytes

Msg 2812, Level 16, State 62, Line 1
Incorrect syntax near '16'.

Answer 15

Julia 1.0 (Tio)

Implementation specific, but this one is made to run in Tio.

ERROR: LoadError: UndefVarError: syntax: extra token "token" after end of expression
Stacktrace:
 [1] include at ./boot.jl:317 [inlined]
 [2] include_relative(::Module, ::String) at ./loading.jl:1038
 [3] include(::Module, ::String) at ./sysimg.jl:29
 [4] exec_options(::Base.JLOptions) at ./client.jl:229
 [5] _start() at ./client.jl:421
in expression starting at /home/runner/.code.tio:1

Try it online!

Answer 16

Brain-flak

Error at character 33: Unclosed '(' character.

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Haskell

[1 of 1] Compiling Main             ( .code.tio.hs, .code.tio.o )

.code.tio.hs:1:4: error: parse error on input ‘of’
  |
1 | [1 of 1] Compiling Main             ( .code.tio.hs, .code.tio.o )
  |    ^^
/srv/wrappers/haskell: line 5: ./.bin.tio: No such file or directory

Try it online!

Stack Cats

Error: invalid character in source code, E | E ,edoc ecruos ni retcarahc dilavni :rorrE

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Taxi

error: parse error: likely incomplete statement

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Hexadecimal Stacking Pseudo-Assembly language

/opt/hspal/hspal.rb:69:in `run': Illegal opcode: 170  (RuntimeError)
    from /opt/hspal/hspal.rb:75:in `<main>'

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Quarterstaff

Traceback (most recent call last):
  File "/opt/quarterstaff/quarterstaff.py", line 142, in <module>
    QuarterstaffInterpreter(open(parser.parse_args().program).read())
  File "/opt/quarterstaff/quarterstaff.py", line 7, in __init__
    self.run(self.parse(program), {}, 0)
  File "/opt/quarterstaff/quarterstaff.py", line 35, in parse
    raise Exception
Exception

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Haxe

Main.hx:1: characters 0-4 : Unexpected Main
Uncaught exception - load.c(181) : Module not found : .bin.tio

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Hasm

Error with instruction <internal{PARSE}> on line 0:
    Syntax error or illegal instruction: Error with instruction <internal{PARSE}> on line 0:
Dumping core:


STACK:
    
OFFSTACK:
    
HEAP:
    0 

Try it online!

Mornington Crescent

Traceback (most recent call last):
  File "/opt/mornington-crescent/esoterpret.py", line 123, in <module>
    arguments.stdin, extra)
  File "/opt/mornington-crescent/esoterpret.py", line 41, in use_language
    while not(interpreter.has_execution_finished()):
  File "/opt/mornington-crescent/modules/morningtoncrescent/morningtoncrescent.py", line 50, in has_execution_finished
    raise RuntimeError("You have to end at Mornington Crescent.")
RuntimeError: You have to end at Mornington Crescent.

Try it online!

Muriel

*** ERROR: muriel: Unknown token '*'

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Just picked some random esolangs from TIO and keyboard hashed until I got an error, then copy + pasted.

Answer 17

Phooey, 21 bytes

Unknown mode for '$'

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Phooey ignores Unknown mode for ', then tries to parse $' which is an unknown mode for $. 😂

Answer 18

Knight (v2 + EVAL) (knight-lang.netlify.app implementation), 32 bytes

Error: Unknown identifier 'rror'

Try it online!

Different implementations handle errors differently (it is undefined behavior in the official specs), which is why I specified the implementation that I'm using.

Also, this technically only works in version 1.x because EVAL is removed as a required function in the v2 official specs, but this implementation has EVAL even though it is a v2 implementation, which is why I specified EVAL in the header just to be safe.

If EVAL wasn't implemented in this implementation, I think something like Error: No value could be parsed! would be a valid error quine instead (and it coincidentally turns out to also be 32 bytes).

Knight (v1.2) (C (gcc) implementation), 21 bytes

invalid character 'i'

Try it online!

Different implementation, different error messages :)

Answer 19

gpg (GnuPG) 2.2.40, 157 bytes

Note error is followed by a newline.

gpg: WARNING: no command supplied.  Trying to guess what you mean ...
gpg: no valid OpenPGP data found.
gpg: processing message failed: Unknown system error

Usage in shell

I don't know if that source is REALLY a program source.

cat <<'X' >source
gpg: WARNING: no command supplied.  Trying to guess what you mean ...
gpg: no valid OpenPGP data found.
gpg: processing message failed: Unknown system error
X
gpg <source >stdout 2>stderr
cat stdout
diff source stderr

Answer 20

ACCUMULATOR, 7 bytes

Invalid

Invalid is the only error in ACCUMULATOR. This is because I is not a function in ACCUMULATOR.

Answer 21

xidoc, 66 bytes

Error while rendering file 
at 2:17-2:18 in []
Command not found: 

xidoc, 135 bytes

Error while rendering file 
at 3:26-3:26
Parse error: Unexpected ']'
3 │ Parse error: Unexpected ']'
  │                          ^

Try it (you need to paste in the code)

Answer 22

Python 3 (IDLE)

SyntaxError: incomplete input

This surprisingly outputs just itself and nothing else.

Answer 23

(,) 38 Bytes

code must be surrounded by parentheses

Litterally the only possible one on my current interpreter

Answer 24

Applescript, 70 bytes

0:2: syntax error: A “:” can’t go after this identifier. (-2740)

Run with osascript -e "0:2: syntax error: A “:” can’t go after this identifier. (-2740)"

Answer 25

YASEPL

ERROR 5 no variable is loaded:(

located at :

very simple

Answer 26

CJam, 12 bytes

u not handled

When operator doesn't exist, interpreter prints * not handled

Answer 27

Elixir

== Compilation error on file e.ex ==
** (SyntaxError) e.ex:3: keyword argument must be followed by space after: ex:
    (elixir) lib/kernel/parallel_compiler.ex:114: anonymous fn/4 in Kernel.ParallelCompiler.spawn_compilers/1

Put the code in e.ex and compile with elixirc e.ex. There are also some blank lines in the output (and in the file), but I can't get them to appear on here; S.O. eats them.

Answer 28

F#

e.fs(1,11): error FS0010: Unexpected symbol ':' in implementation file

Compile with fsc --nologo e.fs. Again, there's an extra blank line I can't properly reproduce here. (Without the --nologo flag the compiler wants to announce itself and its version number and display a Microsoft copyright message.)

Answer 29

Syms, 202 bytes

Traceback (most recent call last):
  File "/opt/syms/syms.py", line 196, in <module>
    stack.append(("{"+str(stack.pop())+"}").replace("\\","\\\\").replace("&","\\&"))
IndexError: pop from empty list

Try it online! Works on TIO. May not work on your configuration.

Answer 30

KSH script, 48 bytes

Save as a file named k.

k[1]: not: not found [No such file or directory]

Try it online! Note that TIO saves KSH scripts as .code.tio, so it's a bit longer but still the same thing.