Restore this message as stderr because it affects requirements.txt generation (#5005)

* Restore this message as stderr because it affects requirements.txt generation.

* Only load the dotenv file when it's a real file, and thus only print the message when it's present.

* Add news fragment.

news/5003.bugfix.rst

@@ -0,0 +1,2 @@
+The text ``Loading .env environment variables...`` has been switched back to stderr as to not
+break requirements.txt generation.  Also it only prints now when a ``.env`` file is actually present.

pipenv/core.py

@@ -115,13 +115,13 @@ def load_dot_env(project, as_dict=False):
             )
         if as_dict:
             return dotenv.dotenv_values(dotenv_file)
-        else:
+        elif os.path.isfile(dotenv_file):
             click.echo(
                 crayons.normal(fix_utf8("Loading .env environment variables..."), bold=True),
-                err=False,
+                err=True,
             )
             dotenv.load_dotenv(dotenv_file, override=True)
-            project.s.initialize()
+        project.s.initialize()
 
 
 def cleanup_virtualenv(project, bare=True):

tests/integration/test_lock.py

@@ -457,7 +457,7 @@ def test_outdated_setuptools_with_pep517_legacy_build_meta_is_updated(PipenvInst
         assert c.returncode == 0
         c = p.pipenv("run python -c 'import setuptools; print(setuptools.__version__)'")
         assert c.returncode == 0
-        assert c.stdout.splitlines()[1] == "40.2.0"
+        assert c.stdout.strip() == "40.2.0"
         c = p.pipenv("install legacy-backend-package")
         assert c.returncode == 0
         assert "vistir" in p.lockfile["default"]
@@ -481,7 +481,7 @@ def test_outdated_setuptools_with_pep517_cython_import_in_setuppy(PipenvInstance
         assert c.returncode == 0
         c = p.pipenv("run python -c 'import setuptools; print(setuptools.__version__)'")
         assert c.returncode == 0
-        assert c.stdout.splitlines()[1] == "40.2.0"
+        assert c.stdout.strip() == "40.2.0"
         c = p.pipenv("install cython-import-package")
         assert c.returncode == 0
         assert "vistir" in p.lockfile["default"]

tests/integration/test_project.py

@@ -189,7 +189,7 @@ def test_run_in_virtualenv_with_global_context(PipenvInstance, virtualenv):
 
         c = p.pipenv("run python -c 'import click;print(click.__file__)'")
         assert c.returncode == 0, (c.stdout, c.stderr)
-        assert is_in_path(c.stdout.splitlines()[1], str(virtualenv)), (c.stdout.splitlines()[1], str(virtualenv))
+        assert is_in_path(c.stdout.strip(), str(virtualenv)), (c.stdout.strip(), str(virtualenv))
 
         c = p.pipenv("clean --dry-run")
         assert c.returncode == 0, (c.stdout, c.stderr)
@@ -210,7 +210,7 @@ def test_run_in_virtualenv(PipenvInstance):
         assert c.returncode == 0
         c = p.pipenv('run python -c "import click;print(click.__file__)"')
         assert c.returncode == 0
-        assert normalize_path(c.stdout.splitlines()[1]).startswith(
+        assert normalize_path(c.stdout.strip()).startswith(
             normalize_path(str(project.virtualenv_location))
         )
         c = p.pipenv("clean --dry-run")

tests/integration/test_run.py

@@ -36,12 +36,12 @@ multicommand = "bash -c \"cd docs && make html\""
         assert c.returncode == 0
         c = p.pipenv('run printfoo')
         assert c.returncode == 0
-        assert c.stdout.splitlines()[1] == 'foo'
+        assert c.stdout.strip() == 'foo'
         assert not c.stderr.strip()
 
         c = p.pipenv('run notfoundscript')
         assert c.returncode != 0
-        assert c.stdout == 'Loading .env environment variables...\n'
+        assert c.stdout == ''
         if os.name != 'nt':     # TODO: Implement this message for Windows.
             assert 'not found' in c.stderr
 
@@ -60,7 +60,7 @@ multicommand = "bash -c \"cd docs && make html\""
             c = p.pipenv("run scriptwithenv")
             assert c.returncode == 0
             if os.name != "nt":  # This doesn't work on CI windows.
-                assert c.stdout.splitlines()[1] == "WORLD"
+                assert c.stdout.strip() == "WORLD"
 
 
 @pytest.mark.run
@@ -80,5 +80,5 @@ def test_run_with_usr_env_shebang(PipenvInstance):
         c = p.pipenv("run ./test_script")
         assert c.returncode == 0
         project = Project()
-        lines = [line.strip() for line in c.stdout.splitlines()[1:]]
+        lines = [line.strip() for line in c.stdout.splitlines()]
         assert all(line == project.virtualenv_location for line in lines)