build_meta.build_sdist should work if the destination directory already contains a tar.gz

[benoit-pierre]

The issue is similar to #1671, see #1745 for how the issue can be resolved.

[pganssle]

@benoit-pierre Do you have a reproducer? I tried using my original reproducer but using python -m pep517.build --source in place of pip wheel, and it had no problem creating two sdists. Not entirely sure why it wasn't a problem, though.

[benoit-pierre]

With an updated version? I suspect it works fine when re-creating the exact same source dist.

[benoit-pierre]

Also, I don't know how pep517.build is implemented.

[pganssle]

With an updated version? I suspect it works fine when re-creating the exact same source dist.

Yeah:

$ ls /tmp/demo_dist_517/dist
foo-0.0.1.tar.gz  foo-0.0.2.tar.gz

Also, I don't know how pep517.build is implemented.

Yeah. I suppose the best reproducer would be an xfail-ing test like the one from #1726 that hits this bug in our minimal PEP 517 build frontend. For now, the only PEP 517 frontends that I know of that build an sdist are tox and pep517.build. If for some reason neither of those hit it that makes this a less important bug to fix, but if it's possible for a valid PEP 517 frontend to hit it, then we should fix it anyway.

[benoit-pierre]

This fail as expected for the sdist case:

 setuptools/tests/test_build_meta.py | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git i/setuptools/tests/test_build_meta.py w/setuptools/tests/test_build_meta.py
index 7612ebd7..38886268 100644
--- i/setuptools/tests/test_build_meta.py
+++ w/setuptools/tests/test_build_meta.py
@@ -157,9 +157,10 @@ def test_build_wheel(self, build_backend):
 
         assert os.path.isfile(os.path.join(dist_dir, wheel_name))
 
-    def test_build_wheel_with_existing_wheel_file_present(self, tmpdir_cwd):
-        # Building a wheel should still succeed if there's already a wheel
-        # in the wheel directory
+    @pytest.mark.parametrize('build_type', ('wheel', 'sdist'))
+    def test_build_with_existing_file_present(self, build_type, tmpdir_cwd):
+        # Building a sdist/wheel should still succeed if there's
+        # already a sdist/wheel in the destination directory.
         files = {
             'setup.py': "from setuptools import setup\nsetup()",
             'VERSION': "0.0.1",
@@ -177,28 +178,30 @@ def test_build_wheel_with_existing_wheel_file_present(self, tmpdir_cwd):
 
         build_files(files)
 
-        dist_dir = os.path.abspath('pip-wheel-preexisting')
+        dist_dir = os.path.abspath('preexisting-' + build_type)
         os.makedirs(dist_dir)
 
-        # make first wheel
         build_backend = self.get_build_backend()
-        wheel_one = build_backend.build_wheel(dist_dir)
+        build_method = getattr(build_backend, 'build_' + build_type)
+
+        # build a first sdist/wheel
+        first_result = build_method(dist_dir)
 
         # change version
         with open("VERSION", "wt") as version_file:
             version_file.write("0.0.2")
 
-        # make *second* wheel
-        wheel_two = self.get_build_backend().build_wheel(dist_dir)
+        # build a *second* sdist/wheel
+        second_result = build_method(dist_dir)
 
-        assert os.path.isfile(os.path.join(dist_dir, wheel_one))
-        assert wheel_one != wheel_two
+        assert os.path.isfile(os.path.join(dist_dir, first_result))
+        assert first_result != second_result
 
-        # and if rebuilding the same wheel?
-        open(os.path.join(dist_dir, wheel_two), 'w').close()
-        wheel_three = self.get_build_backend().build_wheel(dist_dir)
-        assert wheel_three == wheel_two
-        assert os.path.getsize(os.path.join(dist_dir, wheel_three)) > 0
+        # and if rebuilding the exact same sdist/wheel?
+        open(os.path.join(dist_dir, second_result), 'w').close()
+        third_result = build_method(dist_dir)
+        assert third_result == second_result
+        assert os.path.getsize(os.path.join(dist_dir, third_result)) > 0
 
     def test_build_sdist(self, build_backend):
         dist_dir = os.path.abspath('pip-sdist')

[webknjaz]

@pganssle it looks like this should be closed.