Fix Nix Mix

[torhovland]

Describe the bug
The Nix build is currently reporting warnings like this:

trace: warning: crane cannot find name attribute in /nix/store/i70apg8wmqwaw1d20w56yr3hyjvr4f21-source/Cargo.toml, consider setting `pname = "...";` explicitly
trace: warning: crane cannot find version attribute in /nix/store/i70apg8wmqwaw1d20w56yr3hyjvr4f21-source/Cargo.toml, consider setting `version = "...";` explicitly

To Reproduce

nix build

Expected behavior

No warnings or errors.

Additional context

ipetkov/crane#237 (comment)

[Niols]

I don't know how things work in Nix wrt Cargo, but I would tend to blame the fact that pname is set but not version here and here. Since name is pname+version, that should lead to the two errors above.

[torhovland]

See also this: ipetkov/crane#281