This allows one to always override the call to `buildPythonPackage`.
In the following example we create an environment where we have the `blaze` package using an older version of `pandas`. We override first the Python interpreter and pass `packageOverrides` which contains the overrides for packages in
the package set.
```
with import <nixpkgs> {};
(let
python = let
packageOverrides = self: super: {
pandas = super.pandas.overridePythonPackage(old: rec {
version = "0.19.1";
name = "pandas-${version}";
src = super.fetchPypi {
pname = "pandas";
inherit version;
sha256 = "08blshqj9zj1wyjhhw3kl2vas75vhhicvv72flvf1z3jvapgw295";
};
});
};
in pkgs.python3.override {inherit packageOverrides;};
in python.withPackages(ps: [ps.blaze])).env
```
1. 'wrapper' has been renamed to 'wrappedRuby', so use this instead.
2. mkDerivation isn't called with a 'src' attribute, so skip the 'unpackPhase' to avoid an error.
3. Simplify the build command. 'mkdir' and 'patchShebangs' don't need to be called explicitly.
So that helper scripts can be easily sourced in interactive shell
configuration. `autojump` package was already present and had the same
requirements for findind a `share` folders, so I took an inspiration
there.
I beleive this is a better alternative to:
- https://github.com/NixOS/nixpkgs/pull/25080
- https://github.com/NixOS/nixpkgs/pull/27058
Replacing `$out/share/shell` with `$bin/share/fzf` was necessary to
prevent dependency loop in produced derivations.
Packages get --host and --target by default, but can explicitly request
any subset to be passed as needed. See docs for more info.
rustc: Avoid hash breakage by using the old (ignored)
dontSetConfigureCross when not cross building
Improve beam docs:
* correct spelling
* update per pandoc changes
* capitalize titles
* capitalize BEAM throughout and use "the BEAM" when referring to the virtual machine.
* tweak grammar and phrasing
* reformat build-tools-rebar3 section
* add more links
* re-wrap <para>s
Also update <programlisting>s
* normalize whitespace
* don't double quote homepage
* use $ in all shell snippets
The documentation got a bit stale compared to actual contents of
nixpkgs. This commit focuses on updating existing docs, not on making
sure all details of beam packages are covered.
This section gives some details on how to setup an "environment"
without having to go through NixOS (although it could be used there
too). I’ve tried to make it straightforward and have a kind of
"tutorial" feel. Not sure if that’s appropriate for the manual, so any
recommended changes would be helpful.
