Use a different root for fallbacks. Remove old hack that merely checked entrypoint existence (and not if results are valid). Ref #333.

Author: ionelmc

src/setuptools_scm/__init__.py

@@ -34,22 +34,27 @@ def version_from_scm(root):
     return _version_from_entrypoint(config, "setuptools_scm.parse_scm")
 
 
-def _call_entrypoint_fn(config, fn):
+def _call_entrypoint_fn(root, config, fn):
     if function_has_arg(fn, "config"):
-        return fn(config.absolute_root, config=config)
+        return fn(root, config=config)
     else:
         warnings.warn(
             "parse functions are required to provide a named argument"
             " 'config' in the future.",
             category=PendingDeprecationWarning,
             stacklevel=2,
         )
-        return fn(config.absolute_root)
+        return fn(root)
 
 
-def _version_from_entrypoint(config, entrypoint):
-    for ep in iter_matching_entrypoints(config.absolute_root, entrypoint):
-        version = _call_entrypoint_fn(config, ep.load())
+def _version_from_entrypoint(config, entrypoint, fallback=False):
+    if fallback:
+        entrypoint += "_fallback"
+        root = config.fallback_root
+    else:
+        root = config.absolute_root
+    for ep in iter_matching_entrypoints(root, entrypoint):
+        version = _call_entrypoint_fn(root, config, ep.load())
 
         if version:
             return version
@@ -81,20 +86,20 @@ def _do_parse(config):
         return meta(tag=pretended, preformatted=True, config=config)
 
     if config.parse:
-        parse_result = _call_entrypoint_fn(config, config.parse)
+        parse_result = _call_entrypoint_fn(config.absolute_root, config, config.parse)
         if isinstance(parse_result, string_types):
             raise TypeError(
                 "version parse result was a string\nplease return a parsed version"
             )
         version = parse_result or _version_from_entrypoint(
-            config, "setuptools_scm.parse_scm_fallback"
+            config, "setuptools_scm.parse_scm", fallback=True
         )
     else:
         # include fallbacks after dropping them from the main entrypoint
         version = _version_from_entrypoint(
             config, "setuptools_scm.parse_scm"
         ) or _version_from_entrypoint(
-            config, "setuptools_scm.parse_scm_fallback"
+            config, "setuptools_scm.parse_scm", fallback=True
         )
 
     if version:

src/setuptools_scm/config.py

@@ -61,6 +61,7 @@ def __init__(self, relative_to=None, root="."):
         self.write_to = ""
         self.write_to_template = None
         self.fallback_version = None
+        self.fallback_root = _check_absolute_root(".", None)
         self.parse = None
         self.tag_regex = DEFAULT_TAG_REGEX
         self.git_describe_command = None

src/setuptools_scm/integration.py

@@ -2,7 +2,6 @@
 
 from .version import _warn_if_setuptools_outdated
 from .utils import do
-from .discover import iter_matching_entrypoints
 from . import get_version
 
 
@@ -14,12 +13,7 @@ def version_keyword(dist, keyword, value):
         value = {}
     if getattr(value, "__call__", None):
         value = value()
-    # this piece of code is a hack to counter the mistake in root finding
-    matching_fallbacks = iter_matching_entrypoints(
-        ".", "setuptools_scm.parse_scm_fallback"
-    )
-    if any(matching_fallbacks):
-        value.pop("root", None)
+
     dist.metadata.version = get_version(**value)
 
 

testing/test_git.py

@@ -1,3 +1,5 @@
+import sys
+
 from setuptools_scm import integration
 from setuptools_scm.utils import do
 from setuptools_scm import git
@@ -29,6 +31,19 @@ def test_parse_describe_output(given, tag, number, node, dirty):
     assert parsed == (tag, number, node, dirty)
 
 
+def test_root_relative_to(tmpdir, wd, monkeypatch):
+    monkeypatch.delenv("SETUPTOOLS_SCM_DEBUG")
+    p = wd.cwd.ensure("sub/package", dir=1)
+    p.join("setup.py").write(
+        """from setuptools import setup
+setup(use_scm_version={"root": "../..",
+                       "relative_to": __file__})
+"""
+    )
+    res = do((sys.executable, "setup.py", "--version"), p)
+    assert res == "0.1.dev0"
+
+
 @pytest.mark.issue("https://github.com/pypa/setuptools_scm/issues/298")
 def test_file_finder_no_history(wd, caplog):
     file_list = git_find_files(str(wd.cwd))

testing/test_regressions.py

@@ -29,7 +29,7 @@ def test_pkginfo_noscmroot(tmpdir, monkeypatch):
 
     do("git init", p.dirpath())
     res = do((sys.executable, "setup.py", "--version"), p)
-    assert res == "1.0"
+    assert res == "0.1.dev0"
 
 
 def test_pip_egg_info(tmpdir, monkeypatch):