Prop punning when types don't match results in I/O error: _none_: No such file or directory

[mediremi]

For version v12.0.0-alpha.14 (commit e63147f), using component prop punning with mismatched types results in I/O error: _none_: No such file or directory:

module Level2 = {
  @react.component
  let make = (~someProp: float) => {
    React.null
  }
}

module Level1 = {
  @react.component
  let make = (~someProp: array<int>) => {
    <Level2 someProp />
  }
}

FAILED: File.cmj

  We've found a bug for you!
  /home/mediremi/test/File.res

  I/O error: _none_: No such file or directory

In v12.0.0-alpha.12 & v12.0.0-alpha.13, a type error is shown but without any line numbers:

FAILED: File.cmj

  We've found a bug for you!
  /home/mediremi/test/File.res

  This has type: array<int>
  But it's expected to have type: float

(Playground link for v12.0.0-alpha.13)

In v12.0.0-alpha.11 and below, full location information is included in the error:

FAILED: File.cmj

  We've found a bug for you!
  /home/mediremi/test/File.res:11:15-22

   9 │  @react.component
  10 │     let make = (~someProp: array<int>) => {
  11 │       <Level2 someProp />
  12 │     }
  13 │ }

  This has type: array<int>
  But it's expected to have type: float

[mediremi]

The error message is coming from this exception handler in compiler/ml/location.ml:

rescript/compiler/ml/location.ml

Lines 258 to 261 in e63147f

	let () =
	register_error_of_exn (function
	| Sys_error msg ->
	Some (errorf ~loc:(in_file !input_name) "I/O error: %s" msg)

And _none_ comes from the initial value of the input_name ref:

rescript/compiler/ml/location.ml

Line 30 in e63147f

let input_name = ref "_none_"

[mediremi]

If punning isn't used, the error message is fine:

module Level2 = {
  @react.component
  let make = (~someProp: float) => {
    React.null
  }
}

module Level1 = {
  @react.component
  let make = (~someProp: array<int>) => {
    <Level2 someProp=someProp />
  }
}

FAILED: File.cmj

  We've found a bug for you!
  /home/mediremi/test/File.res:11:24-31

   9 │  @react.component
  10 │     let make = (~someProp: array<int>) => {
  11 │       <Level2 someProp=someProp />
  12 │     }
  13 │ }

  This has type: array<int>
  But it's expected to have type: float

Playground link

[nojaf]

I have a hunch. Let me check later tonight