Builtin error function gives misleading message

[tpoliaw]

As far as I can make out, the error builtin function provides a way for recipes to bail out with a message if some pre-conditions are not met. When used, the message given to the user suggests the error function failed rather than the surrounding recipe.

Example (very contrived) justfile

demo arg:
    {{ if arg == "foo" { error("arg cannot be 'foo'") } else { arg } }}

other:
    mkdir /cant/make/root/directories

Running this as just demo foo, gives the output

error: call to function `error` failed: arg cannot be 'foo'
 ——▶ justfile:5:28
  │
5 │     {{ if arg == "foo" { error("arg cannot be 'foo'") } else { arg } }}
  │                          ^^^^^

Both the "call to function `error` failed" and the code snippet make the error look like it was at a lower level than it was.

Would it be possible to make the error more similar to other recipe errors

error: recipe `demo` failed on line 5: arg cannot be 'foo'

to match the other recipe from the above example

mkdir /cant/make/root/directories
mkdir: cannot create directory ‘/cant/make/root/directories’: No such file or directory
error: recipe `other` failed on line 9 with exit code 1

[casey]

Thanks for the report! I just merged #3705, which removes the function name from all function error messages, so the original error message will now be:

error: arg cannot be 'foo'
 ——▶ justfile:5:28
  │
5 │     {{ if arg == "foo" { error("arg cannot be 'foo'") } else { arg } }}
  │                          ^^^^^

I think call to function `foo` failed was mostly just noise, which made error messages harder to read, and in the case of the error function, incorrectly indicated that the error function itself was at fault.

There isn't an easy way to provide better context, for example, the specific recipe or line that failed, since functions can be called in all sorts of contexts. Hopefully, however, this is an improvement.

[tpoliaw]

That's great, thanks for the quick fix