buildPythonPackage: refactor

8 files changed, 149 insertions, 111 deletions

diff --git a/doc/languages-frameworks/python.md b/doc/languages-frameworks/python.md
index fc0100c5f2d5..e7a8b034a112 100644
--- a/doc/languages-frameworks/python.md
+++ b/doc/languages-frameworks/python.md
@@ -523,7 +523,7 @@ All parameters from `mkDerivation` function are still supported.
 * `postShellHook`: Hook to execute commands after `shellHook`.
 * `makeWrapperArgs`: A list of strings. Arguments to be passed to `makeWrapper`, which wraps generated binaries. By default, the arguments to `makeWrapper` set `PATH` and `PYTHONPATH` environment variables before calling the binary. Additional arguments here can allow a developer to set environment variables which will be available when the binary is run. For example, `makeWrapperArgs = ["--set FOO BAR" "--set BAZ QUX"]`.
 * `installFlags`: A list of strings. Arguments to be passed to `pip install`. To pass options to `python setup.py install`, use `--install-option`. E.g., `installFlags=["--install-option='--cpp_implementation'"].
-* `format`: Format of the source. Options are `setup` for when the source has a `setup.py` and `setuptools` is used to build a wheel, and `wheel` in case the source is already a binary wheel. The default value is `setup`.
+* `format`: Format of the source. Valid options are `setuptools` (default), `flit`, `wheel`, and `other`. `setuptools` is for when the source has a `setup.py` and `setuptools` is used to build a wheel, `flit`, in case `flit` should be used to build a wheel, and `wheel` in case a wheel is provided. In case you need to provide your own `buildPhase` and `installPhase` you can use `other`.
 * `catchConflicts` If `true`, abort package build if a package name appears more than once in dependency tree. Default is `true`.
 * `checkInputs` Dependencies needed for running the `checkPhase`. These are added to `buildInputs` when `doCheck = true`.
 
diff --git a/pkgs/development/interpreters/python/build-python-package-common.nix b/pkgs/development/interpreters/python/build-python-package-common.nix
new file mode 100644
index 000000000000..80d40013f157
--- /dev/null
+++ b/pkgs/development/interpreters/python/build-python-package-common.nix
@@ -0,0 +1,27 @@
+# This function provides generic bits to install a Python wheel.
+
+{ python
+, bootstrapped-pip
+}:
+
+{ buildInputs ? []
+# Additional flags to pass to "pip install".
+, installFlags ? []
+, ... } @ attrs:
+
+attrs // {
+  buildInputs = buildInputs ++ [ bootstrapped-pip ];
+
+  installPhase = attrs.installPhase or ''
+    runHook preInstall
+
+    mkdir -p "$out/${python.sitePackages}"
+    export PYTHONPATH="$out/${python.sitePackages}:$PYTHONPATH"
+
+    pushd dist
+    ${bootstrapped-pip}/bin/pip install *.whl --no-index --prefix=$out --no-cache ${toString installFlags}
+    popd
+
+    runHook postInstall
+  '';
+}
\ No newline at end of file
diff --git a/pkgs/development/interpreters/python/build-python-package-flit.nix b/pkgs/development/interpreters/python/build-python-package-flit.nix
new file mode 100644
index 000000000000..8628c3df769e
--- /dev/null
+++ b/pkgs/development/interpreters/python/build-python-package-flit.nix
@@ -0,0 +1,19 @@
+# This function provides specific bits for building a flit-based Python package.
+
+{ flit
+}:
+
+{ ... } @ attrs:
+
+attrs // {
+  buildInputs = [ flit ];
+  buildPhase = attrs.buildPhase or ''
+    runHook preBuild
+    flit wheel
+    runHook postBuild
+  '';
+
+  # Flit packages do not come with tests.
+  installCheckPhase = attrs.checkPhase or ":";
+  doCheck = attrs.doCheck or false;
+}
\ No newline at end of file
diff --git a/pkgs/development/interpreters/python/build-python-package-setuptools.nix b/pkgs/development/interpreters/python/build-python-package-setuptools.nix
new file mode 100644
index 000000000000..f077533ecfe4
--- /dev/null
+++ b/pkgs/development/interpreters/python/build-python-package-setuptools.nix
@@ -0,0 +1,56 @@
+# This function provides specific bits for building a setuptools-based Python package.
+
+{ lib
+, python
+, bootstrapped-pip
+}:
+
+{
+# passed to "python setup.py build_ext"
+# https://github.com/pypa/pip/issues/881
+  setupPyBuildFlags ? []
+# Execute before shell hook
+, preShellHook ? ""
+# Execute after shell hook
+, postShellHook ? ""
+, ... } @ attrs:
+
+let
+  # use setuptools shim (so that setuptools is imported before distutils)
+  # pip does the same thing: https://github.com/pypa/pip/pull/3265
+  setuppy = ./run_setup.py;
+
+in attrs // {
+  # we copy nix_run_setup.py over so it's executed relative to the root of the source
+  # many project make that assumption
+  buildPhase = attrs.buildPhase or ''
+    runHook preBuild
+    cp ${setuppy} nix_run_setup.py
+    ${python.interpreter} nix_run_setup.py ${lib.optionalString (setupPyBuildFlags != []) ("build_ext " + (lib.concatStringsSep " " setupPyBuildFlags))} bdist_wheel
+    runHook postBuild
+  '';
+
+  installCheckPhase = attrs.checkPhase or ''
+    runHook preCheck
+    ${python.interpreter} nix_run_setup.py test
+    runHook postCheck
+  '';
+
+  # Python packages that are installed with setuptools
+  # are typically distributed with tests.
+  # With Python it's a common idiom to run the tests
+  # after the software has been installed.
+  doCheck = attrs.doCheck or true;
+
+  shellHook = attrs.shellHook or ''
+    ${preShellHook}
+    if test -e setup.py; then
+      tmp_path=$(mktemp -d)
+      export PATH="$tmp_path/bin:$PATH"
+      export PYTHONPATH="$tmp_path/${python.sitePackages}:$PYTHONPATH"
+      mkdir -p $tmp_path/${python.sitePackages}
+      ${bootstrapped-pip}/bin/pip install -e . --prefix $tmp_path
+    fi
+    ${postShellHook}
+  '';
+}
\ No newline at end of file
diff --git a/pkgs/development/interpreters/python/build-python-package-wheel.nix b/pkgs/development/interpreters/python/build-python-package-wheel.nix
new file mode 100644
index 000000000000..7be0a4c304a3
--- /dev/null
+++ b/pkgs/development/interpreters/python/build-python-package-wheel.nix
@@ -0,0 +1,20 @@
+# This function provides specific bits for building a wheel-based Python package.
+
+{
+}:
+
+{ ... } @ attrs:
+
+attrs // {
+  unpackPhase = ''
+    mkdir dist
+    cp $src dist/"''${src#*-}"
+  '';
+
+  # Wheels are pre-compiled
+  buildPhase = attrs.buildPhase or ":";
+  installCheckPhase = attrs.checkPhase or ":";
+
+  # Wheels don't have any checks to run
+  doCheck = attrs.doCheck or false;
+}
\ No newline at end of file
diff --git a/pkgs/development/interpreters/python/build-python-package.nix b/pkgs/development/interpreters/python/build-python-package.nix
index a92296cedbaa..e15405e2981d 100644
--- a/pkgs/development/interpreters/python/build-python-package.nix
+++ b/pkgs/development/interpreters/python/build-python-package.nix
@@ -7,120 +7,31 @@
 , python
 , mkPythonDerivation
 , bootstrapped-pip
+, flit
 }:
 
-{ buildInputs ? []
-
-# propagate build dependencies so in case we have A -> B -> C,
-# C can import package A propagated by B
-#, propagatedBuildInputs ? []
-
-# passed to "python setup.py build_ext"
-# https://github.com/pypa/pip/issues/881
-, setupPyBuildFlags ? []
-
-# Execute before shell hook
-, preShellHook ? ""
-
-# Execute after shell hook
-, postShellHook ? ""
-
-# Additional flags to pass to "pip install".
-, installFlags ? []
-
-, format ? "setup"
-
+let
+  setuptools-specific = import ./build-python-package-setuptools.nix { inherit lib python bootstrapped-pip; };
+  flit-specific = import ./build-python-package-flit.nix { inherit flit; };
+  wheel-specific = import ./build-python-package-wheel.nix { };
+  common = import ./build-python-package-common.nix { inherit python bootstrapped-pip; };
+in
+
+{
+# Several package formats are supported.
+# "setuptools" : Install a common setuptools/distutils based package. This builds a wheel.
+# "wheel" : Install from a pre-compiled wheel.
+# "flit" : Install a flit package. This builds a wheel.
+# "other" : Provide your own buildPhase and installPhase.
+format ? "setuptools"
 , ... } @ attrs:
 
-
-
-
 let
-  # use setuptools shim (so that setuptools is imported before distutils)
-  # pip does the same thing: https://github.com/pypa/pip/pull/3265
-  setuppy = ./run_setup.py;
-
   formatspecific =
-    if format == "wheel" then
-      {
-        unpackPhase = ''
-          mkdir dist
-          cp $src dist/"''${src#*-}"
-        '';
-
-        # Wheels are pre-compiled
-        buildPhase = attrs.buildPhase or ":";
-        installCheckPhase = attrs.checkPhase or ":";
-
-        # Wheels don't have any checks to run
-        doCheck = attrs.doCheck or false;
-      }
-    else if format == "setup" then
-      {
-        # we copy nix_run_setup.py over so it's executed relative to the root of the source
-        # many project make that assumption
-        buildPhase = attrs.buildPhase or ''
-          runHook preBuild
-          cp ${setuppy} nix_run_setup.py
-          ${python.interpreter} nix_run_setup.py ${lib.optionalString (setupPyBuildFlags != []) ("build_ext " + (lib.concatStringsSep " " setupPyBuildFlags))} bdist_wheel
-          runHook postBuild
-        '';
-
-        installCheckPhase = attrs.checkPhase or ''
-          runHook preCheck
-          ${python.interpreter} nix_run_setup.py test
-          runHook postCheck
-        '';
-
-        # Python packages that are installed with setuptools
-        # are typically distributed with tests.
-        # With Python it's a common idiom to run the tests
-        # after the software has been installed.
-        doCheck = attrs.doCheck or true;
-      }
-    else
-      throw "Unsupported format ${format}";
-
-in mkPythonDerivation ( attrs // {
-
-  # To build and install a wheel we need pip
-  buildInputs = buildInputs ++ [ bootstrapped-pip ];
-
-#inherit propagatedBuildInputs;
-
-  configurePhase = attrs.configurePhase or ''
-    runHook preConfigure
-
-    # patch python interpreter to write null timestamps when compiling python files
-    # this way python doesn't try to update them when we freeze timestamps in nix store
-    export DETERMINISTIC_BUILD=1
-
-    runHook postConfigure
-  '';
-
-  installPhase = attrs.installPhase or ''
-    runHook preInstall
-
-    mkdir -p "$out/${python.sitePackages}"
-    export PYTHONPATH="$out/${python.sitePackages}:$PYTHONPATH"
-
-    pushd dist
-    ${bootstrapped-pip}/bin/pip install *.whl --no-index --prefix=$out --no-cache ${toString installFlags}
-    popd
-
-    runHook postInstall
-  '';
-
-  shellHook = attrs.shellHook or ''
-    ${preShellHook}
-    if test -e setup.py; then
-       tmp_path=$(mktemp -d)
-       export PATH="$tmp_path/bin:$PATH"
-       export PYTHONPATH="$tmp_path/${python.sitePackages}:$PYTHONPATH"
-       mkdir -p $tmp_path/${python.sitePackages}
-       ${bootstrapped-pip}/bin/pip install -e . --prefix $tmp_path
-    fi
-    ${postShellHook}
-  '';
+    if format == "setuptools" then common (setuptools-specific attrs)
+    else if format == "flit" then common (flit-specific attrs)
+    else if format == "wheel" then common (wheel-specific attrs)
+    else if format == "other" then {}
+    else throw "Unsupported format ${format}";
 
-} // formatspecific)
+in mkPythonDerivation ( attrs // formatspecific )
\ No newline at end of file
diff --git a/pkgs/development/interpreters/python/mk-python-derivation.nix b/pkgs/development/interpreters/python/mk-python-derivation.nix
index 0f798c63e8fa..c8fedaf75fc9 100644
--- a/pkgs/development/interpreters/python/mk-python-derivation.nix
+++ b/pkgs/development/interpreters/python/mk-python-derivation.nix
@@ -57,6 +57,10 @@ python.stdenv.mkDerivation (builtins.removeAttrs attrs ["disabled"] // {
 
   inherit pythonPath;
 
+  # patch python interpreter to write null timestamps when compiling python files
+  # this way python doesn't try to update them when we freeze timestamps in nix store
+  DETERMINISTIC_BUILD=1;
+
   buildInputs = [ wrapPython ] ++ buildInputs ++ pythonPath
     ++ [ (ensureNewerSourcesHook { year = "1980"; }) ]
     ++ (lib.optional (lib.hasSuffix "zip" attrs.src.name or "") unzip)
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 3575018870f3..122042072755 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -30,6 +30,7 @@ let
   buildPythonPackage = makeOverridable (callPackage ../development/interpreters/python/build-python-package.nix {
     inherit mkPythonDerivation;
     inherit bootstrapped-pip;
+    flit = self.flit;
   });
 
   buildPythonApplication = args: buildPythonPackage ({namePrefix="";} // args );