top-level: Remove cycles: stdenv calls in top-level but not vice versa

This commit changes the dependencies of stdenv, and clean-up the stdenv
story by removing the `defaultStdenv` attribute as well as the `bootStdenv`
parameter.

Before, the final bootstrapping stage's stdenv was provided by
all-packages, which was iterating multiple times over the
top-level/default.nix expression, and non-final bootstrapping stages'
stdenvs were explicitly specified with the `bootStdenv` parameter.

Now, all stages' stdenvs are specified with the `stdenv` parameter.
For non-final bootstrapping stages, this is a small change---basically just
rename the parameter.
For the final stage, top-level/default.nix takes the chosen stdenv and
makes the final stage with it.

`allPackages` is used to make all bootstrapping stages, final and
non-final alike. It's basically the expression of `stage.nix` (along with a
few partially-applied default arguments)

Note, the make-bootstrap-tools scripts are temporarily broken

1 files changed, 2 insertions, 1 deletions

diff --git a/pkgs/stdenv/linux/default.nix b/pkgs/stdenv/linux/default.nix
index e3aeafe178d3..e0a68bdca2f3 100644
--- a/pkgs/stdenv/linux/default.nix
+++ b/pkgs/stdenv/linux/default.nix
@@ -107,7 +107,8 @@ rec {
 
       thisPkgs = allPackages {
         inherit system platform;
-        bootStdenv = thisStdenv;
+        allowCustomOverrides = false;
+        stdenv = thisStdenv;
       };
 
     in { stdenv = thisStdenv; pkgs = thisPkgs; };