Package: libgcc-8-dev Version: 8.4.0-2 Severity: grave The latest version of gcc-8 is not installable because libgcc-8-dev depends on libgcc-s1 (>= 1:8.4.0-2), but the version of libgcc-s1 in the archive does not have an epoch and is therefore too low to fulfill this requirement.
The same holds for libgcc-7-dev 7.5.0-6.