I am getting an nnpchecker error in a build: [new release] dream-html (0.0.2) by yawaramin · Pull Request #23786 · ocaml/opam-repository · GitHub The message is: #=== ERROR while compiling dream-html.0.0.2 ===================================# # context 2.2.0~alpha~dev | linux/x86_64 |…

Here is a non-complete method. It only catches some uses of naked pointers, but some that seem to be common. Download the source of all dependencies, with something like:opam install --download-only dream Grep the sources for all possible (value) casts in C files:grep -r --include \*.h --include…

Thanks. It looks like the binary is dune itself so I guess I can scan it with the nnpchecker. Kinda surprising that dune would be messing with C pointers though. I’ll try later today.

If the binary at fault is dune, then it would be great to make an issue on the dune issue tracker. Naked pointers are bugs in OCaml 5.

[image] yawaramin: (cd _build/default/test && ./dream_html_test.exe) > _build/default/test/got.html # Out-of-heap pointer at 0x55dd1c32e210 of value 0x55dd1c1d2180 has non-black head (tag=65) According to the log, I think I don’t think the issue is in dune itself. It’s in dream_html_test.exe …

Thanks for the analysis. If you have rr installed on your machine, it is fairly easy to get the source of this out-of-heap pointer.

Thanks for the pointer (no pun intended). Although, that is puzzling because the test is just building an HTML data structure, converting it to a string, and printing it to standard output: let node = ... let () = node |> to_string |> print_endline In fact, we can see that it ran successfully beca…

[image] yawaramin: So, I am actually hesitant to conclude that the issue is even in my test executable Your executable is probably fine, but one of the libraries you’re linking against might use naked pointers.

Thanks very much for that analysis! After looking at rr I realized it’s Linux only so I can’t use it on Mac. I filed an issue with ocaml-ssl: Naked pointer - ocaml_ssl_get_current_cipher · Issue #143 · savonet/ocaml-ssl · GitHub EDIT: looks like you had already found this in the analysis for your p…

As this is marked with an x it looks like I actually missed it :slight_smile: That’s probably a side-effect of this being tedious and time-consuming.

I just found another interesting tidbit: other pure-OCaml libraries built on Dream seem to be exposing the same nnpchecker error, e.g. [new release] dream-htmx (0.1.0) by beajeanm · Pull Request #21954 · ocaml/opam-repository · GitHub So…clearly it’s not specific to my library. I will try submittin…

Nnpchecker error–how to debug?

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kayceesrk May 16, 2023, 2:46pm 2

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Nnpchecker error–how to debug?

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