Control: reopen 955144 I'm reopening this because libclang-dev is uninstallable in a pure unstable system due to gcc bug #954826, and the intended solution to #954826 seems to be to remove gcc 8, after which libclang-dev will still be uninstallable.
Workaround: install libobjc-8-dev, libgcc-8-dev, libstdc++-8-dev from testing, and do not let them be upgraded to unstable. Sylvestre Ledru wrote: > sudo apt install libclang-dev -t unstable > Reading package lists... Done > Building dependency tree > Reading state information... Done > The following additional packages will be installed: > libclang-9-dev (1:9.0.1-10) > The following NEW packages will be installed: > libclang-9-dev (1:9.0.1-10) > libclang-dev (1:9.0-49.1) > 0 upgraded, 2 newly installed, 0 to remove and 407 not upgraded. > Need to get 16.1 MB of archives. > After this operation, 151 MB of additional disk space will be used. > Do you want to continue? [Y/n] I think this is because you have packages from testing installed. If you don't, you get something like this (I'm testing in a relatively minimal autopkgtest VM created by vmdebootstrap, but piuparts or buildds would have similar issues): # dpkg-query -W (204 packages, see https://paste.debian.net/1137522/ if the full list matters to you) # apt install libclang-dev ... The following packages have unmet dependencies: libclang-dev : Depends: libclang-9-dev (>= 9~) but it is not going to be installed (...after pulling on the thread a bit...) # apt install libclang-dev libclang-9-dev libobjc-8-dev libgcc-8-dev libstdc++-8-dev ... The following packages have unmet dependencies: libgcc-8-dev : Depends: libgcc-s1 (>= 1:8.4.0-2) but 10-20200324-1 is to be installed I think the options to resolve this bug are: - Move llvm-toolchain-9 from gcc-8 development libraries to -9 or -10 (I don't know whether this is a simple binNMU or whether it needs more intrusive changes) - Change the default to llvm-toolchain-10, as has already happened in unstable - Convince the gcc-8 maintainer to fix #954826 by removing the epoch from the dependency (and possibly disabling gnat, since apparently gnat-8 is no longer available) instead of by removing the package I hope this helps, smcv
