If meta.outputsToInstall is set to include absent outputs, various
tools break including channel updates and nix-env.
grahamc@Morbo> nix-env -i -f . -A elf-header-real
installing 'elf-header'
error: this derivation has bad 'meta.outputsToInstall'
This patch verifies each value in meta.outputsToInstall is a valid
output. It validates this condition only if checkMeta is true.
grahamc@Morbo> nix-build . -A elf-header-real
error: Package ‘elf-header’ in /home/grahamc/projects/nixpkgs/pkgs/development/libraries/elf-header/default.nix:36 has invalid meta.outputsToInstall, refusing to evaluate.
The package elf-header has set meta.outputsToInstall to: bin
however elf-header only has the outputs: out
and is missing the following ouputs:
- bin
(use '--show-trace' to show detailed location information)
Note, now the nix-env experience is decidedly worse for users who have
checkMeta set to true:
grahamc@Morbo> nix-env -i -f . -A elf-header-real; echo $?
0
though since this is already an issue for unfree, broken, unsupported,
and insecure validity problems I'm not sure we should do something
different here.