The condition does not match the comment, and therefore not the original
intention. It currently returns early in *any* type of Nix shell, not
just pure ones, including 'nix develop'.
Besides being unnecessary, this check prevents Nix shells from
functioning properly. For instance, it causes the initialization of the
Zsh fpath to be skipped, which is critical. The fact that the user is
unable to opt out of this behaviour makes this an ever bigger problem
since /etc/zshenv is being loaded unconditionally by Zsh.
For reference, NixOS does not perform such check, and apparently never
did.
When a script specifies the shell option "nounset" as part of the
shebang (e.g., via "#!/usr/bin/env -S zsh -u"), our initialization
scripts would produce error messages of the form:
__ETC_FOO_SOURCED: parameter not set
These messages could probably be confusing to users when running such
scripts. By providing a fall-back in the parameter expansion, we can
avoid them.
This patch does not address interactive shell start-up, where such
messages may (or may not) be less problematic.
NixOS/nixpkgs@7d84dbdf5b
Currently zshenv by default only sets fpath without exporting it. A
parent shell would also not set those variables usually as they are
shell local.
It also sources a file called set-environment but this is protected by
an environment variable called __NIX_DARWIN_SET_ENVIRONMENT_DONE. Hence
any modification done by the parent shell should persist as long as
__NIX_DARWIN_SET_ENVIRONMENT_DONE is not unset.
This behavior deviates from what we do in bashrc and breaks common
setups such as tmux/mosh or screen.
NixOS/nixpkgs@55819e6c86
Zsh ships some rudimentary completions for programs where upstream also
ships their own completions (e.g., curl). So as not to shadow those
completions, we need to prepend to the fpath instead of appending.
NixOS/nixpkgs@8dad5a2239
This process was automated by [my fork of `nix-doc-munge`]; thanks
to @pennae for writing this tool! It automatically checks that the
resulting documentation doesn't change, although my fork loosens
this a little to ignore some irrelevant whitespace and typographical
differences.
As of this commit there is no DocBook remaining in the options
documentation.
You can play along at home if you want to reproduce this commit:
$ NIX_PATH=nixpkgs=flake:nixpkgs/c1bca7fe84c646cfd4ebf3482c0e6317a0b13f22 \
nix shell nixpkgs#coreutils \
-c find . -name '*.nix' \
-exec nix run github:emilazy/nix-doc-munge/0a7190f600027bf7baf6cb7139e4d69ac2f51062 \
{} +
[my fork of `nix-doc-munge`]: https://github.com/emilazy/nix-doc-munge
This should enable `nix run` to work under shells like fish and zsh,
as well as making child shells not needlessly reset any environment
that should be inherited.
Implementation adapted from NixOS.
Don't extend initial PATH adding extra entries should be done through
appending environment.systemPath or manually extending it with
environment.extraInit or similar options.
