Fatal error: exception Invalid_argument("String.sub / Bytes.sub")

[giraud]

I have a reasonml/reason-react project that compiles ok with bs-platform 8.4.2. First step is I want to upgrade compiler to rescript 9.1.4. After updating dependencies I do a yarn rescript build and I got several fatal errors on different sources.

ex:

Fatal error: exception Invalid_argument("String.sub / Bytes.sub")
rescript: [434/645] src/grid/TextHeaderRenderer3.ast

this is the only message I got even with -verbose. same error with -with-deps

[bobzhang]

this seems to be a parsing error, is that source code in reason or rescript syntax, is it available?

[giraud]

If it's a parser issue, I should be able to get more info about the error, it's location, etc. Is there a way to get that ?

[cristianoc]

Trying setting environment variable OCAMLRUNPARAM=b to see a stack trace.

[bobzhang]

it could be a bug, see similar issues: https://github.com/rescript-lang/syntax/pull/435

[giraud]

@cristianoc will try next week

[giraud]

This is what I get:

Fatal error: exception Invalid_argument("String.sub / Bytes.sub")
Raised at file "pervasives.ml", line 33, characters 20-45
Called from file "string.ml" (inlined), line 47, characters 2-23
Called from file "super_code_frame.ml", line 141, characters 4-93
Called from file "super_location.ml", line 67, characters 10-183
Called from file "format.ml", line 1276, characters 4-20
Called from file "format.ml", line 1286, characters 32-48
Called from file "format.ml", line 1286, characters 32-48
Called from file "format.ml", line 1276, characters 4-20
Called from file "format.ml", line 1276, characters 4-20
Called from file "format.ml", line 1276, characters 4-20
Called from file "format.ml", line 1337, characters 20-38
Called from file "list.ml", line 100, characters 12-15
Called from file "ast_iterator.ml", line 97, characters 4-28
Called from file "list.ml", line 100, characters 12-15
Called from file "ast_iterator.ml", line 505, characters 8-31
Called from file "list.ml", line 100, characters 12-15
Called from file "ppx_entry.ml", line 59, characters 6-65
Called from file "js_implementation.ml", line 219, characters 2-140
Called from file "rescript_compiler_main.ml", line 57, characters 5-258
Called from file "rescript_compiler_main.ml", line 496, characters 4-90
Re-raised at file "location.ml", line 311, characters 14-25
Re-raised at file "location.ml", line 311, characters 14-25
Re-raised at file "location.ml", line 311, characters 14-25
Re-raised at file "location.ml", line 311, characters 14-25
Re-raised at file "location.ml", line 311, characters 14-25
Re-raised at file "location.ml", line 311, characters 14-25
Called from file "location.ml" (inlined), line 316, characters 31-61
Called from file "rescript_compiler_main.ml", line 506, characters 6-37

the code is closed source and is a mix between reason/rescript.

[cristianoc]

Looks like something crashing when looking at lines around the error, in super-errors. ++ @chenglou

[giraud]

reproducible steps:

• checkout bs-css (master branch)
• yarn
• cd bs-css
• yarn re:build -> ok
• in Css_Js_Core.rei change let unsafe: (string, string) => rule; to let unsafe: (. string, string) => rule; but dont change it in impl
• yarn re:build -> exception

[bobzhang]

in general, error reporting should not trigger an exception, we will provide a fallback on this

[bobzhang]

can not reproduce on 9.1.4. This may be a windows specific issue, can you confirm with that?

[giraud]

On holidays, I'll test next week

[giraud]

@bobzhang it seems to be a Windows issue. I tested the repro case in Ubuntu with yarn, and I got a correct error reporting:

FAILED: src/Css_Js_Core.cmj

  We've found a bug for you!
  /home/dev/bs-css/bs-css/src/Css_Js_Core.re:1092:5-10

  1090 │   );
  1091 │ 
  1092 │ let unsafe = (property, value) => D(property, value);
  1093 │ 
  1094 │ let userSelect = x =>

  The implementation /home/dev/bs-css/bs-css/src/Css_Js_Core.re
       does not match the interface src/Css_Js_Core.cmi:
       Values do not match:
         let unsafe: (string, string) => rule
       is not included in
         let unsafe: (. string, string) => rule
       File "/home/dev/bs-css/bs-css/src/Css_Js_Core.rei", line 77, characters 1-95:
         Expected declaration
       File "/home/dev/bs-css/bs-css/src/Css_Js_Core.re", line 1092, characters 5-11:
         Actual declaration

rescript: [31/36] src/Css_Legacy_Core.cmj

also, on Windows, same behavior with yarn or npm.

[bobzhang]

@giraud It seems super_errors are not robust to handle some invalid input, on Windows you can set BS_VSCODE=1 the env variable to bypass the super errors reporting as a work around.

[giraud]

I confirm I get a correct error output with that env var. is there a place where all these variables are explained ?

[bobzhang]

@giraud This is not supposed to be used. It is that super_errors are buggy, so I added it for a work around.

[giraud]

it seems interesting for ide integration 😄

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.