Bootstrapping from full tarballs fails with gcc-10

[glondu]

The latest full source release tarball fails with gcc-10 (in current Debian testing) because of the embedded OCaml copy (4.07.1) that fails because of multiple definitions.

See ocaml/ocaml#9144

A new tarball release should be made.

[avsm]

There is a fix on the 2.0 branch (#4262) that shifts the cold compiler to 4.09 and avoids this problem. This is pending a opam 2.0.8 release.

How urgent is this for you? I thought Debian didn't use the full source release tarball for generating the opam package.

[glondu]

How urgent is this for you?

I found a workaround (adding -cc "gcc -fcommon" to the ./configure call), so it is not that urgent now...

I thought Debian didn't use the full source release tarball for generating the opam package.

Indeed. I noticed that when updating the script opam-bootstrap.sh in Belenios.

[avsm]

Glad you found a workaround; let us know if you're blocked on anything else. I'll leave this open until we release opam 2.0.8 with the fix.

[glondu]

let us know if you're blocked on anything else

My workaround for #3987 is to uninstall dune, which is not very satisfactory...

[dra27]

I think this has been fixed just by winding the "cold" version of OCaml forwards