Add version into setup call (#1104)

The core pytket project uses setuptools_scm to extract
version information from .git. This would be awkward in
Nix as it would involve copying the .git directory into
the pytket source.

As we already have the version extracted from another
file in the project, which is used to set the version
number on the Nix side, we can instead hardcode this
version number into setup.py when copying it to the
derivation source.

Co-authored-by: Alec Edgington <[email protected]>

nix-support/pytket.nix

@@ -6,7 +6,7 @@ let
   version = if builtins.length versions > 0 then
     builtins.elemAt versions 0
   else
-    "0.0.0";
+    builtins.trace "Warning: Unable to find version. Defaulting to 0.0.0" "0.0.0";
 
   jsonschema-4180 = super.python3Packages.jsonschema.overrideAttrs (_: rec {
     version = "4.18.0";
@@ -35,7 +35,7 @@ in {
     '';
   };
   pytket = super.python3.pkgs.buildPythonPackage {
-    name = "pytket";
+    pname = "pytket";
     inherit version;
     propagatedBuildInputs = with super.python3.pkgs; [
       self.binders
@@ -53,19 +53,24 @@ in {
 
     unpackPhase = ''
       cp -r ${../pytket/pytket} pytket;
-      cp -r ${../pytket/setup.py} setup.py;
-      cp -r ${../pytket/package.md} package.md;
+      cp ${../pytket/package.md} package.md;
       cp -r ${../schemas} schemas;
+
+      # The usual build depends on setuptools-scm to extract the version.
+      # We have already extracted the version within nix, so we can simply
+      # inject it into setup.py.
+      cat ${../pytket/setup.py} | sed 's/setup(/setup(version="${version}",/' > setup.py;
+
       mkdir test_root;
       cp -r ${../pytket/tests} test_root/tests;
+      # hardcode the version extracted from docs/conf.py.
+      chmod 755 pytket
+      echo '__version__ = "${version}"' > pytket/_version.py;
     '';
     preBuild = ''
       export USE_NIX=1;
     '';
     postFixup = ''
-      # hardcode the version extracted from docs/conf.py.
-      echo '__version__ = "${version}"' > $out/lib/python3.10/site-packages/pytket/_version.py;
-
       # these directories aren't copied by setup.py, so we do it manually
       cp -r ${
         ../pytket/pytket/circuit/display/js