nix-env can read priorities from a derivations meta attributes, but this
only works when installing a nix expression.
nix-env can also install bare store paths, however meta attributes are
not readable in that case. This means that a store path can not be
installed with a specific priority.
Some cases where it is advantageous to install a store path: a remote
host following a `nix copy`, or any time you want to save some
evaluation time and happen to already know the store path.
This PR addresses this shortcoming by adding a --priority flag to
nix-env --install.
The experimental `nix eval` command already supports a `--raw` flag.
This commit implements the same flag for the stable nix-instantiate command.
Until now instructions and scripts that didn't want to rely on experimental
features had to use workarounds such as:
nix-instantiate --eval <something> | tr -d \"
(which also undesirably also removes double quotation marks within the string), or
nix-instantiate --eval <something> | jq -j
(which undesirably depends on another package).
Co-authored-by: Silvan Mosberger <silvan.mosberger@tweag.io>
* doc: Clarify that nix-shell still uses shell from host environment
* doc: Fix NIX_BUILD_SHELL description
* doc: Add anchor and link to NIX_BUILD_SHELL
* doc: Add example of default shell trickiness
Co-authored-by: Valentin Gagarin <valentin@gagarin.work>
