[Nix-dev] remove manifest on nixos

[Mathijs Kwik]

Hi all,

I noticed the package "okular" can't open pdf files.
I found that the binary isn't linked to poppler/poppler-qt (the .nix
expression looks ok and uses popplerQt4 as input).

Not sure if that's the problem, but as a first test, I would like to
recompile it and look at warnings in the output.
However, okular is already in the manifest, so reinstalling it will
just get this same binary version again.
nix-env does have a "prebuilt-only" flag, but I couldn't find "no-prebuilt".

"nix-channel --list" doesn't list any channels, so probably channels
are built-in in nixos.
so nix-channel --remove won't help me.

How should I proceed?

Thanks,
Mathijs