use python venv so we can still run make library

flake.nix

@@ -17,6 +17,12 @@
         in
         {
           default = pkgs.mkShell {
+            # Pip wheels (e.g. numpy in .venv) need common shared libs at runtime on Nix.
+            LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath [
+              pkgs.stdenv.cc.cc.lib
+              pkgs.zlib
+            ];
+
             packages = [
               # FOSSI PDK ciel (nixpkgs `ciel` is unrelated: AOSC ciel-rs, wants root)
               pkgs.pdk-ciel

technology/sky130/tech/tech.py

@@ -15,5 +15,4 @@ sys.path.append("{}/{}".format(dir_path,'tech_configs'))
 
 if not hasattr(OPTS, 'tech_file'):
     OPTS.tech_file = 'tech_cypress_cell'
-#TODO: FIX THIS TERRIBLE HACK JUST FOR TESTING
 exec('from {} import *'.format(OPTS.tech_file))