buh,. that build failure is going to be nasty...

The issue is that 99-check-remove-rpms removes all installed packages, with a minimal set of things it keeps.

we have

shell=`chroot $BUILD_ROOT rpm --qf '%{NAME}\n' -qf /usr/bin/sh|sort -u`
…
    case ${PKG} in
    libgcc*|libgomp*|libstdc++*)
        ;;
    $coreutils|$utillinux|$shell|$findutils|$gzip|$cpio)
        ;;
    bash-legacybin*|glibc-usrmerge-bootstrap-helper)
        ;;
    pam_unix*)
        ;;
    rpm|rpm-build|rpm-ndb)
        ;;
    *)
        RPM_ERASE_LIST="$RPM_ERASE_LIST $PKG"
        ;;
    esac

so the package containing /usr/bin/sh is being kept (dash-sh), BUT not the package containing the symlink where /usr/bin/sh points to.

With bash this was never an issue, as bash is a preinstall package and always there for the OBS build - and thus explicitly not uninstalled due to other rules.

The other one we have in the setup so far is busybox/busybox-sh, but there the layout is also different, as busybox-sh as built by busybox-links.spec, which buildrequires busybox. So the 'target' of the link is thus in the buildroot without our package, thus not tripping over it.

The best would probably be to check if /usr/bin/sh is a symlink and if it is, try to follow it and stop removing the owning package of the link target too (bash in this case)

The 2nd best is to follow the structure of busybox and produce dash-sh in a sep spec file, buildRequiring/Requiring dash