I looked at other direct uses of make_symbol in emit.mlp files, and saw no instance of a similar bug. (It would be nice to have a dedicated type for symbols different than string, and in particular it would rule this error out).

Anyone willing to formally approve ?

Done.

Thanks! Will merge once CI passes.

OK, there is an issue with the ^ in the filename (actually two) under Windows:

1. ocamltest needed to handle this when calling diff to compare the outputs. I pushed a commit with a fix.
2. flexdll needs to be adapted to handle this special character.

Since synchronizing with flexdll will be difficult, I suggest we remove the caret from the file name.

@nojb I think that the use of Filename.quote_command is a pretty nice fix. Shouldn't we also use it in other places where Sys.command is used in the distribution? Now that you are drawing attention to it, I am a bit worried about, for example, in ocamltest/main.ml:

Sys.command ("rm -rf " ^ test_build_directory_prefix)

This could turn into a disaster if there is a quoting problem in the argument.

Other uses have the general foo > bar form you fixed, including one in the toplevel.

I think it could be nice to try to adapt all relevant uses of Sys.command, possibly in a separate PR.

I think it could be nice to try to adapt all relevant uses of Sys.command, possibly in a separate PR.

Indeed, I will prepare a separate PR for that. I removed the ocamltest fix from this PR, as it is not needed as I removed the caret from the file name. I will include it in the coming PR.

Am (still) planning to merge this as soon as CI passes :)

Very good, thanks!

The test breaks under openbsd/freebsd in INRIA's CI; fix in #9473

(It would be nice to have a dedicated type for symbols different than string, and in particular it would rule this error out).

To this end, have a look at @mshinwell's RFC.