[20.09] nixUnstable: 2.4pre20201205_a5d85d0 -> 2.4pre20210308_1c0e3e4, hydra-unstable: 2020-10-20 -> 2021-03-10

[Ma27]

Motivation for this change

Backport of #114786.
Also had to backport most recent lowdown bumps to get Nix compiling.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[sternenseemann]

lowdown-related changes look good to me, the breaking changes in 0.8.0 are as follows:

• Library API changes for functions that may fail due to allocation errors. This is what nixUnstable actually needs and fine since no other package currently depends on lowdown as a library
• The --nroff-hardwrap option got removed. This is most likely a breakage fine to backport since it is reasonably obscure.

[roberth]

no other package currently depends on lowdown as a library

Not in Nixpkgs perhaps. For a simple package like lowdown, isn't it just as easy to duplicate it, so we have a lowdown_0_8 package next to the old lowdown?

[shlevy]

Not a big deal especially on a maintenance branch, but would be nice to have the lowdown fixes in first so we don't have a known-broken commit in the history.

[r-rmcgibbo]

Result of nixpkgs-review pr 115947 at 82f018b7 run on aarch64-linux 1

5 packages marked as broken and skipped:

• disnix
• disnixos
• hydra-unstable
• nixFlakes
• nixUnstable

2 packages built successfully:

• hydra-migration
• lowdown

---

Result of nixpkgs-review pr 115947 at 82f018b7 run on x86_64-linux 1

6 packages built successfully:

• disnix
• disnixos
• hydra-migration
• hydra-unstable
• lowdown
• nixFlakes
(nixUnstable)

[sternenseemann]

Not in Nixpkgs perhaps. For a simple package like lowdown, isn't it just as easy to duplicate it, so we have a lowdown_0_8 package next to the old lowdown?

FWIW the lowdown library is pretty seldomly used where the lowdown utility and nix are the only known downstream users to the library's author afaik. But agreed, a lowdown_0_8 attribute would be the cleaner solution.

[Ma27]

FWIW the lowdown library is pretty seldomly used where the lowdown utility and nix are the only known downstream users to the library's author afaik. But agreed, a lowdown_0_8 attribute would be the cleaner solution.

Done.

Not a big deal especially on a maintenance branch, but would be nice to have the lowdown fixes in first so we don't have a known-broken commit in the history.

Done.