Merge pull request #297628 from cwp/python-env-venv

Fix venv creation in Python environments 

9 files changed, 82 insertions, 72 deletions

diff --git a/pkgs/development/interpreters/python/cpython/2.7/default.nix b/pkgs/development/interpreters/python/cpython/2.7/default.nix
index dda254fca3894..86b09fa877685 100644
--- a/pkgs/development/interpreters/python/cpython/2.7/default.nix
+++ b/pkgs/development/interpreters/python/cpython/2.7/default.nix
@@ -318,8 +318,6 @@ in with passthru; stdenv.mkDerivation ({
     inherit passthru;
 
     postFixup = ''
-      # Include a sitecustomize.py file. Note it causes an error when it's in postInstall with 2.7.
-      cp ${../../sitecustomize.py} $out/${sitePackages}/sitecustomize.py
     '' + lib.optionalString strip2to3 ''
       rm -R $out/bin/2to3 $out/lib/python*/lib2to3
     '' + lib.optionalString stripConfig ''
diff --git a/pkgs/development/interpreters/python/cpython/default.nix b/pkgs/development/interpreters/python/cpython/default.nix
index 4a0533536c84a..e96685016b25c 100644
--- a/pkgs/development/interpreters/python/cpython/default.nix
+++ b/pkgs/development/interpreters/python/cpython/default.nix
@@ -537,8 +537,7 @@ in with passthru; stdenv.mkDerivation (finalAttrs: {
     # Strip tests
     rm -R $out/lib/python*/test $out/lib/python*/**/test{,s}
     '' + optionalString includeSiteCustomize ''
-    # Include a sitecustomize.py file
-    cp ${../sitecustomize.py} $out/${sitePackages}/sitecustomize.py
+
     '' + optionalString stripBytecode ''
     # Determinism: deterministic bytecode
     # First we delete all old bytecode.
diff --git a/pkgs/development/interpreters/python/pypy/default.nix b/pkgs/development/interpreters/python/pypy/default.nix
index 9b414944bba5b..5724f4944d9c2 100644
--- a/pkgs/development/interpreters/python/pypy/default.nix
+++ b/pkgs/development/interpreters/python/pypy/default.nix
@@ -126,9 +126,6 @@ in with passthru; stdenv.mkDerivation rec {
     ln -s $out/${executable}-c/include $out/include/${libPrefix}
     ln -s $out/${executable}-c/lib-python/${if isPy3k then "3" else pythonVersion} $out/lib/${libPrefix}
 
-    # Include a sitecustomize.py file
-    cp ${../sitecustomize.py} $out/${if isPy38OrNewer then sitePackages else "lib/${libPrefix}/${sitePackages}"}/sitecustomize.py
-
     runHook postInstall
   '';
 
diff --git a/pkgs/development/interpreters/python/pypy/prebuilt.nix b/pkgs/development/interpreters/python/pypy/prebuilt.nix
index 4b47c642eca4c..70f8711ef0866 100644
--- a/pkgs/development/interpreters/python/pypy/prebuilt.nix
+++ b/pkgs/development/interpreters/python/pypy/prebuilt.nix
@@ -95,9 +95,6 @@ in with passthru; stdenv.mkDerivation {
     echo "Removing bytecode"
     find . -name "__pycache__" -type d -depth -delete
 
-    # Include a sitecustomize.py file
-    cp ${../sitecustomize.py} $out/${sitePackages}/sitecustomize.py
-
     runHook postInstall
   '';
 
diff --git a/pkgs/development/interpreters/python/pypy/prebuilt_2_7.nix b/pkgs/development/interpreters/python/pypy/prebuilt_2_7.nix
index 37a06f9f61ed5..f0b60c2333f56 100644
--- a/pkgs/development/interpreters/python/pypy/prebuilt_2_7.nix
+++ b/pkgs/development/interpreters/python/pypy/prebuilt_2_7.nix
@@ -96,9 +96,6 @@ in with passthru; stdenv.mkDerivation {
     echo "Removing bytecode"
     find . -name "__pycache__" -type d -depth -delete
 
-    # Include a sitecustomize.py file
-    cp ${../sitecustomize.py} $out/${sitePackages}/sitecustomize.py
-
     runHook postInstall
   '';
 
diff --git a/pkgs/development/interpreters/python/sitecustomize.py b/pkgs/development/interpreters/python/sitecustomize.py
deleted file mode 100644
index d79a4696d8eaa..0000000000000
--- a/pkgs/development/interpreters/python/sitecustomize.py
+++ /dev/null
@@ -1,39 +0,0 @@
-"""
-This is a Nix-specific module for discovering modules built with Nix.
-
-The module recursively adds paths that are on `NIX_PYTHONPATH` to `sys.path`. In
-order to process possible `.pth` files `site.addsitedir` is used.
-
-The paths listed in `PYTHONPATH` are added to `sys.path` afterwards, but they
-will be added before the entries we add here and thus take precedence.
-
-Note the `NIX_PYTHONPATH` environment variable is unset in order to prevent leakage.
-
-Similarly, this module listens to the environment variable `NIX_PYTHONEXECUTABLE`
-and sets `sys.executable` to its value.
-"""
-import site
-import sys
-import os
-import functools
-
-paths = os.environ.pop('NIX_PYTHONPATH', None)
-if paths:
-    functools.reduce(lambda k, p: site.addsitedir(p, k), paths.split(':'), site._init_pathinfo())
-
-# Check whether we are in a venv or virtualenv. 
-# For Python 3 we check whether our `base_prefix` is different from our current `prefix`.
-# For Python 2 we check whether the non-standard `real_prefix` is set.
-# https://stackoverflow.com/questions/1871549/determine-if-python-is-running-inside-virtualenv
-in_venv = (sys.version_info.major == 3 and sys.prefix != sys.base_prefix) or (sys.version_info.major == 2 and hasattr(sys, "real_prefix"))
-
-if not in_venv:
-    executable = os.environ.pop('NIX_PYTHONEXECUTABLE', None)
-    prefix = os.environ.pop('NIX_PYTHONPREFIX', None)
-
-    if 'PYTHONEXECUTABLE' not in os.environ and executable is not None:
-        sys.executable = executable
-    if prefix is not None:
-        # Sysconfig does not like it when sys.prefix is set to None
-        sys.prefix = sys.exec_prefix = prefix
-        site.PREFIXES.insert(0, prefix)
diff --git a/pkgs/development/interpreters/python/tests.nix b/pkgs/development/interpreters/python/tests.nix
index df4484f9ec68e..0251a903a7ae8 100644
--- a/pkgs/development/interpreters/python/tests.nix
+++ b/pkgs/development/interpreters/python/tests.nix
@@ -39,11 +39,21 @@ let
         is_virtualenv = "False";
       };
     } // lib.optionalAttrs (!python.isPyPy) {
-      # Use virtualenv from a Nix env.
-      nixenv-virtualenv = rec {
-        env = runCommand "${python.name}-virtualenv" {} ''
-          ${pythonVirtualEnv.interpreter} -m virtualenv venv
-          mv venv $out
+      # Use virtualenv with symlinks from a Nix env.
+      nixenv-virtualenv-links = rec {
+        env = runCommand "${python.name}-virtualenv-links" {} ''
+          ${pythonVirtualEnv.interpreter} -m virtualenv --system-site-packages --symlinks --no-seed $out
+        '';
+        interpreter = "${env}/bin/${python.executable}";
+        is_venv = "False";
+        is_nixenv = "True";
+        is_virtualenv = "True";
+      };
+    } // lib.optionalAttrs (!python.isPyPy) {
+      # Use virtualenv with copies from a Nix env.
+      nixenv-virtualenv-copies = rec {
+        env = runCommand "${python.name}-virtualenv-copies" {} ''
+          ${pythonVirtualEnv.interpreter} -m virtualenv --system-site-packages --copies --no-seed $out
         '';
         interpreter = "${env}/bin/${python.executable}";
         is_venv = "False";
@@ -59,27 +69,48 @@ let
         is_nixenv = "True";
         is_virtualenv = "False";
       };
-    } // lib.optionalAttrs (python.isPy3k && (!python.isPyPy)) {
-      # Venv built using plain Python
+    } // lib.optionalAttrs (python.pythonAtLeast "3.8" && (!python.isPyPy)) {
+      # Venv built using links to plain Python
       # Python 2 does not support venv
       # TODO: PyPy executable name is incorrect, it should be pypy-c or pypy-3c instead of pypy and pypy3.
-      plain-venv = rec {
-        env = runCommand "${python.name}-venv" {} ''
-          ${python.interpreter} -m venv $out
+      plain-venv-links = rec {
+        env = runCommand "${python.name}-venv-links" {} ''
+          ${python.interpreter} -m venv --system-site-packages --symlinks --without-pip $out
+        '';
+        interpreter = "${env}/bin/${python.executable}";
+        is_venv = "True";
+        is_nixenv = "False";
+        is_virtualenv = "False";
+      };
+    } // lib.optionalAttrs (python.pythonAtLeast "3.8" && (!python.isPyPy)) {
+      # Venv built using copies from plain Python
+      # Python 2 does not support venv
+      # TODO: PyPy executable name is incorrect, it should be pypy-c or pypy-3c instead of pypy and pypy3.
+      plain-venv-copies = rec {
+        env = runCommand "${python.name}-venv-copies" {} ''
+          ${python.interpreter} -m venv --system-site-packages --copies --without-pip $out
         '';
         interpreter = "${env}/bin/${python.executable}";
         is_venv = "True";
         is_nixenv = "False";
         is_virtualenv = "False";
       };
-
     } // lib.optionalAttrs (python.pythonAtLeast "3.8") {
       # Venv built using Python Nix environment (python.buildEnv)
-      # TODO: Cannot create venv from a  nix env
-      # Error: Command '['/nix/store/ddc8nqx73pda86ibvhzdmvdsqmwnbjf7-python3-3.7.6-venv/bin/python3.7', '-Im', 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit status 1.
-      nixenv-venv = rec {
-        env = runCommand "${python.name}-venv" {} ''
-          ${pythonEnv.interpreter} -m venv $out
+      nixenv-venv-links = rec {
+        env = runCommand "${python.name}-venv-links" {} ''
+          ${pythonEnv.interpreter} -m venv --system-site-packages --symlinks --without-pip $out
+        '';
+        interpreter = "${env}/bin/${pythonEnv.executable}";
+        is_venv = "True";
+        is_nixenv = "True";
+        is_virtualenv = "False";
+      };
+    } // lib.optionalAttrs (python.pythonAtLeast "3.8") {
+      # Venv built using Python Nix environment (python.buildEnv)
+      nixenv-venv-copies = rec {
+        env = runCommand "${python.name}-venv-copies" {} ''
+          ${pythonEnv.interpreter} -m venv --system-site-packages --copies --without-pip $out
         '';
         interpreter = "${env}/bin/${pythonEnv.executable}";
         is_venv = "True";
@@ -91,11 +122,33 @@ let
     testfun = name: attrs: runCommand "${python.name}-tests-${name}" ({
       inherit (python) pythonVersion;
     } // attrs) ''
+      mkdir $out
+
+      # set up the test files
       cp -r ${./tests/test_environments} tests
       chmod -R +w tests
       substituteAllInPlace tests/test_python.py
-      ${attrs.interpreter} -m unittest discover --verbose tests #/test_python.py
-      mkdir $out
+
+      # run the tests by invoking the interpreter via full path
+      echo "absolute path: ${attrs.interpreter}"
+      ${attrs.interpreter} -m unittest discover --verbose tests 2>&1 | tee "$out/full.txt"
+
+      # run the tests by invoking the interpreter via $PATH
+      export PATH="$(dirname ${attrs.interpreter}):$PATH"
+      echo "PATH: $(basename ${attrs.interpreter})"
+      "$(basename ${attrs.interpreter})" -m unittest discover --verbose tests 2>&1 | tee "$out/path.txt"
+
+      # make sure we get the right path when invoking through a result link
+      ln -s "${attrs.env}" result
+      relative="result/bin/$(basename ${attrs.interpreter})"
+      expected="$PWD/$relative"
+      actual="$(./$relative -c "import sys; print(sys.executable)" | tee "$out/result.txt")"
+      if [ "$actual" != "$expected" ]; then
+        echo "expected $expected, got $actual"
+        exit 1
+      fi
+
+      # if we got this far, the tests passed
       touch $out/success
     '';
 
diff --git a/pkgs/development/interpreters/python/tests/test_environments/test_python.py b/pkgs/development/interpreters/python/tests/test_environments/test_python.py
index 0fc4b8a9e91c1..538273f65dbc7 100644
--- a/pkgs/development/interpreters/python/tests/test_environments/test_python.py
+++ b/pkgs/development/interpreters/python/tests/test_environments/test_python.py
@@ -38,7 +38,7 @@ class TestCasePython(unittest.TestCase):
 
     @unittest.skipIf(IS_PYPY or sys.version_info.major==2, "Python 2 does not have base_prefix")
     def test_base_prefix(self):
-        if IS_VENV or IS_NIXENV or IS_VIRTUALENV:
+        if IS_VENV or IS_VIRTUALENV:
             self.assertNotEqual(sys.prefix, sys.base_prefix)
         else:
             self.assertEqual(sys.prefix, sys.base_prefix)
diff --git a/pkgs/development/interpreters/python/wrapper.nix b/pkgs/development/interpreters/python/wrapper.nix
index f5f9b03e0fd3c..aa568a01b1b0c 100644
--- a/pkgs/development/interpreters/python/wrapper.nix
+++ b/pkgs/development/interpreters/python/wrapper.nix
@@ -35,6 +35,8 @@ let
       fi
       mkdir -p "$out/bin"
 
+      rm -f $out/bin/.*-wrapped
+
       for path in ${lib.concatStringsSep " " paths}; do
         if [ -d "$path/bin" ]; then
           cd "$path/bin"
@@ -42,7 +44,13 @@ let
             if [ -f "$prg" ]; then
               rm -f "$out/bin/$prg"
               if [ -x "$prg" ]; then
-                makeWrapper "$path/bin/$prg" "$out/bin/$prg" --set NIX_PYTHONPREFIX "$out" --set NIX_PYTHONEXECUTABLE ${pythonExecutable} --set NIX_PYTHONPATH ${pythonPath} ${lib.optionalString (!permitUserSite) ''--set PYTHONNOUSERSITE "true"''} ${lib.concatStringsSep " " makeWrapperArgs}
+                if [ -f ".$prg-wrapped" ]; then
+                  echo "#!${pythonExecutable}" > "$out/bin/$prg"
+                  sed -e '1d' -e '3d' ".$prg-wrapped" >> "$out/bin/$prg"
+                  chmod +x "$out/bin/$prg"
+                else
+                  makeWrapper "$path/bin/$prg" "$out/bin/$prg" --inherit-argv0 --resolve-argv0 ${lib.optionalString (!permitUserSite) ''--set PYTHONNOUSERSITE "true"''} ${lib.concatStringsSep " " makeWrapperArgs}
+                fi
               fi
             fi
           done