Relevance of OCaml LLVM bindings as packaged in llvm-toolchain-*

[Adrian Bunk]

On Mon, Jun 01, 2026 at 10:35:22AM +0200, Stéphane Glondu wrote:
>...
> Every OCaml transition is delayed by several weeks (or months) because of
> LLVM. This is due to OCaml LLVM bindings being built and installed by
> llvm-toolchain-*.
>...

While OCaml is where you are seeing it, this issue also affects plenty 
of other transitions.

E.g. the transision to make Python 3.14 the default (#1130323) is 
blocked for 3 months like your OCaml transition, and for the same
LLVM reasons.

We had an LLVM maintainer complain that it took the release team 1 month
to ACK the abseil transition.[1] Now it's 1.5 months later, and the sole
reason why the abseil transition still isn't finished are the same
LLVM 19 issues that currently block your OCaml transition.

I'd guess the root problem is a lack of awareness by the LLVM 
maintainers that the LLVM packages are pretty core, and FTBFS
or failure to migrate can cause real pain for many other people.

LLVM 21 started depending on LLVM 22 when the latter entered unstable,
but LLVM 22 was only able to migrate after the issues (especially
autopkgtests) were fixed 3 months later. 

The unloved packages of the LLVM maintainers are versions older than the 
latest LLVM version, the fixes for the LLVM 19 issues that block the 
OCaml and Python transitions are in git for nearly a month.

Removing an old LLVM version is work (not just bug reports) for fixing 
packages (including key packages), as long as this work has not been
done by anyone an old LLVM version needs some basic maintainance.

> Cheers,

cu
Adrian

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1127773#53