fix #479: better error on unparsable simplified semver version

3 files changed, 17 insertions, 1 deletions

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index c5c57dd..0d7a1c3 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,8 @@
 v4.2.0
 ======
 
+
+* fix #479: raise indicative error when tags carry non-parsable information
 * Add `no-guess-dev` which does no next version guessing, just adds `.post1.devN` in
   case there are new commits after the tag
 * add python3.9
diff --git a/src/setuptools_scm/version.py b/src/setuptools_scm/version.py
index ac74149..c58be7e 100644
--- a/src/setuptools_scm/version.py
+++ b/src/setuptools_scm/version.py
@@ -247,7 +247,12 @@ def guess_next_dev_version(version):
 
 
 def guess_next_simple_semver(version, retain, increment=True):
-    parts = [int(i) for i in str(version).split(".")[:retain]]
+    try:
+        parts = [int(i) for i in str(version).split(".")[:retain]]
+    except ValueError:
+        raise ValueError(
+            "{version} can't be parsed as numeric version".format(version=version)
+        )
     while len(parts) < retain:
         parts.append(0)
     if increment:
diff --git a/testing/test_version.py b/testing/test_version.py
index aaaf952..38c98bf 100644
--- a/testing/test_version.py
+++ b/testing/test_version.py
@@ -49,6 +49,15 @@ def test_next_semver(version, expected_next):
     assert computed == expected_next
 
 
+def test_next_semver_bad_tag():
+
+    version = meta("1.0.0-foo", config=c)
+    with pytest.raises(
+        ValueError, match="1.0.0-foo can't be parsed as numeric version"
+    ):
+        simplified_semver_version(version)
+
+
 @pytest.mark.parametrize(
     "version, expected_next",
     [