bug#31719: Chains of dependencies getting longer

[Andreas Enge]

Hello,

trying a "guix build openjdk", I see this:
2136.0 MB would be downloaded:
   /gnu/store/243algr6h60j46spn5dqhjc4mhkd0a0p-libelf-0.8.13
   /gnu/store/ymyvcc0871lwbnkv5acf5lldv0ahm5z1-openjdk-9.181-jdk
   /gnu/store/3hb80r2l48ix8pq2kvcsr1i9aj76d681-openjdk-9.181
   /gnu/store/52bp22jrvwfqa5fmlv2y5vxcir74m8jb-openjdk-10.46-jdk
   /gnu/store/bp86qd2vgaqahqam3n89xl1wz02g0srs-openjdk-10.46
   /gnu/store/a8f5ksk3gb4i1wrn7m5fm5ijc0zwwg2w-openjdk-11.28-jdk
   /gnu/store/9ni61z4nhvkrxbzj6gwip8zrb7zbkx6l-openjdk-11.28
   /gnu/store/837pl2vmq9haiw3kmsnh72fkwvcljipk-openjdk-12.33-jdk
   /gnu/store/ll5dgf42x9smclrc1mx4gyk3dl683m77-openjdk-13.0-jdk
   /gnu/store/bjvy5ab6f0gff52m808vzcn3rw55yxjn-openjdk-14.0-doc
   /gnu/store/r8kxk031fighc4dxr57nl0wirzhk8v08-openjdk-14.0-jdk
   /gnu/store/25kx1vna763xh4mpszp4p4sy4j6iifs3-openjdk-14.0

So the problem is getting worse and worse over time, which makes a solution
more important.

Andreas