pip-build-hook.sh: Support $pipBuildFlags

doc/languages-frameworks/python.section.md

@@ -1189,6 +1189,8 @@ following are specific to `buildPythonPackage`:
 * `pipInstallFlags ? []`: A list of strings. Arguments to be passed to `pip
   install`. To pass options to `python setup.py install`, use
   `--install-option`. E.g., `pipInstallFlags=["--install-option='--cpp_implementation'"]`.
+* `pipBuildFlags ? []`: A list of strings. Arguments to be passed to `pip
+  wheel`.
 * `pythonPath ? []`: List of packages to be added into `$PYTHONPATH`. Packages
   in `pythonPath` are not propagated (contrary to `propagatedBuildInputs`).
 * `preShellHook`: Hook to execute commands before `shellHook`.

pkgs/development/interpreters/python/hooks/pip-build-hook.sh

@@ -1,13 +1,22 @@
 # Setup hook to use for pip projects
 echo "Sourcing pip-build-hook"
 
+declare -a pipBuildFlags
+
 pipBuildPhase() {
     echo "Executing pipBuildPhase"
     runHook preBuild
 
     mkdir -p dist
     echo "Creating a wheel..."
-    @pythonInterpreter@ -m pip wheel --verbose --no-index --no-deps --no-clean --no-build-isolation --wheel-dir dist .
+    @pythonInterpreter@ -m pip wheel \
+       --verbose \
+       --no-index \
+       --no-deps \
+       --no-clean \
+       --no-build-isolation \
+       --wheel-dir dist \
+       $pipBuildFlags .
     echo "Finished creating a wheel..."
 
     runHook postBuild