Bug#955039: llvm-dev doesn't ensure that the corresponding clang is installed

[Sylvestre Ledru]

Le 27/03/2020 à 11:12, Iain Lane a écrit :
> Package: llvm-dev
> Version: 1:10.0-50~exp1
> Severity: normal
> 
> Hi there,
> 
> Please see the attached build log. It's from mozjs68 which has
> Build-Depends: llvm-dev, clang.
> 
>    Get: 73 https://mirrors.wikimedia.org/debian unstable/main s390x clang-10 s390x 1:10.0.0-1 [104 kB]
>    Get: 74 https://mirrors.wikimedia.org/debian experimental/main s390x clang s390x 1:10.0-50~exp1 [8132 B]
>    ...
>    Get: 97 https://mirrors.wikimedia.org/debian experimental/main s390x libclang-dev s390x 1:10.0-50~exp1 [7756 B]
>    ...
>    Get: 116 https://mirrors.wikimedia.org/debian unstable/main s390x llvm-9-tools s390x 1:9.0.1-10 [322 kB]
>    Get: 117 https://mirrors.wikimedia.org/debian unstable/main s390x llvm-9-dev s390x 1:9.0.1-10 [25.2 MB]
>    Get: 118 https://mirrors.wikimedia.org/debian unstable/main s390x llvm-dev s390x 1:9.0-49.1 [8052 B

> and then later on the build failed with:
> 
>    ERROR: The file /usr/lib/llvm-9/bin/clang returned by `llvm-config --bindir` does not exist.
> 
> It ultimately happened because of #954826 meaning clang-9 is
> uninstallable ATM. But it would be good if the packaging of llvm could
> somehow ensure that the matching clang is always installed - in this
> case, it would have required installing llvm-10-dev. I don't actually
> see how to achieve this in consuming packages.


Not sure how to fix it correctly.
I don't want to introduce a new dependency on clang (I don't think llvm-dev is part of the dependency tree).

Here, the problem seems to be the experimental/unstable mix.

Suggestions welcome!
Cheers
S