From 5357724b57453beb27ee40800f904b2741931c9e Mon Sep 17 00:00:00 2001
From: Miro Hrončok <miro@hroncok.cz>
Date: Jan 19 2022 10:18:35 +0000
Subject: Python: Add a warning about git tarballs and setuptools_scm


---

diff --git a/guidelines/modules/ROOT/pages/Python.adoc b/guidelines/modules/ROOT/pages/Python.adoc
index 0cb0c12..43eebd4 100644
--- a/guidelines/modules/ROOT/pages/Python.adoc
+++ b/guidelines/modules/ROOT/pages/Python.adoc
@@ -1136,6 +1136,16 @@ When using sources from PyPI,
 you can use the <<pypi_source,the `+%pypi_source+` macro>>
 to generate the proper URL.
 
+WARNING: Some Python packages use `git`
+(or a similar version control system)
+to determine the version,
+for example via https://pypi.org/project/setuptools-scm/[setuptools_scm].
+When using sources from PyPI,
+the git-derived version information is usually hardcoded in some file.
+When using a tarball from a git forge,
+the version information is missing and must be manually provided by the packager,
+e.g. by setting the `SETUPTOOLS_SCM_PRETEND_VERSION` environment variable in `+%generate_buildrequires+` and `+%build+` sections of the spec file.
+
 == Example spec file[[_example_python_spec_file]]
 
 The following is a viable spec file