From fec81c89087f2ddc153cdb7dcdd2ed2c89b03b0b Mon Sep 17 00:00:00 2001
From: Sam Grayson <sam@samgrayson.me>
Date: Fri, 7 Apr 2023 10:15:47 -0600
Subject: [PATCH 1/2] Add edgecases

---
 docs/edgecases.md | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/docs/edgecases.md b/docs/edgecases.md
index 0ef8750..e195462 100644
--- a/docs/edgecases.md
+++ b/docs/edgecases.md
@@ -192,3 +192,24 @@ Resulting override:
   );
 }
 ```
+
+#### Nix evaluation errors
+
+1. Enable `--show-trace`.
+2. Remove packages from the `pyproject.toml`, `rm poetry.lock && nix shell nixpkgs#poetry --command poetry lock`.
+3. Try running poetry2nix again.
+
+By these means, one can bisect the package-set to find the problematic package.
+
+One error you might run into is an "infinite recursion encountered." If this error indicates this happens happens `while evaluating the attribute 'propagatedBuildInputs' of the derivation 'python${version}-${pkg_name}'`, then it is possible `${pkg_name}` has a recursive dependency.
+
+For example, this is the abbreviated error message if I try to install `dask[distributed]`:
+
+```
+error: infinite recursion encountered
+       … while evaluating the attribute 'propagatedBuildInputs' of the derivation 'python3.11-distributed-2023.3.2'
+       … while evaluating the attribute 'propagatedBuildInputs' of the derivation 'python3.11-dask-2023.3.2'
+       … while evaluating the attribute 'propagatedBuildInputs' of the derivation 'python3.11-main-0.1.0'
+```
+
+This is because `dask[distributed]` depends on `distributed` which depends on `dask`. The solution is to install `dask` (no extras) and `distributed` separately.
\ No newline at end of file

From df434f193afc467f06183465804d1d9d9f602b8a Mon Sep 17 00:00:00 2001
From: Sam Grayson <sam@samgrayson.me>
Date: Fri, 7 Apr 2023 10:38:47 -0600
Subject: [PATCH 2/2] Add Nix expression for multiple overrides

---
 docs/edgecases.md | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/docs/edgecases.md b/docs/edgecases.md
index e195462..e49f278 100644
--- a/docs/edgecases.md
+++ b/docs/edgecases.md
@@ -167,6 +167,33 @@ poetry2nix.mkPoetryApplication {
 }
 ```
 
+If you need very many of these overrides or you need to use them twice, consider using something like this. It has less repetition:
+
+```nix
+let
+  pypkgs-build-requirements = {
+    tox = [ "hatchling" "hatch-vcs" ];
+    universal-pathlib = [ "flit-core" ];
+    pygithub = [ "setuptools-scm" ];
+    beautifulsoup4 = [ "hatchling" ];
+    xyzservices = [ "setuptools" ];
+    simpervisor = [ "setuptools" ];
+    pandas = [ "versioneer" ];
+  };
+  p2n-overrides = p2n.defaultPoetryOverrides.extend (self: super:
+    builtins.mapAttrs (package: build-requirements:
+      (builtins.getAttr package super).overridePythonAttrs (old: {
+        buildInputs = (old.buildInputs or [ ]) ++ (builtins.map (pkg: if builtins.isString pkg then builtins.getAttr pkg super else pkg) build-requirements);
+      })
+    ) pypkgs-build-requirements
+  );
+in
+  poetry2nix.mkPoetryApplication {
+    projectDir = ./.;
+    overrides = p2n-overrides;
+  }
+```
+
 We recommend that you contribute your changes to `poetry2nix` so that other users can profit from them as well.
 The specific file with the upstream overrides is [build-systems.json](https://github.com/nix-community/poetry2nix/blob/master/overrides/build-systems.json). It is a simple JSON file which contains the overrides in an array and sorted in alphabetical order.