Try to generate a version from Meson

Author: QuLogic

lib/matplotlib/__init__.py

@@ -219,15 +219,20 @@ def _get_version():
     if ((root / ".matplotlib-repo").exists()
             and (root / ".git").exists()
             and not (root / ".git/shallow").exists()):
-        import setuptools_scm
-        return setuptools_scm.get_version(
-            root=root,
-            version_scheme="release-branch-semver",
-            local_scheme="node-and-date",
-            fallback_version=_version.version,
-        )
-    else:  # Get the version from the _version.py setuptools_scm file.
-        return _version.version
+        try:
+            import setuptools_scm
+        except ImportError:
+            pass
+        else:
+            return setuptools_scm.get_version(
+                root=root,
+                version_scheme="release-branch-semver",
+                local_scheme="node-and-date",
+                fallback_version=_version.version,
+            )
+    # Get the version from the _version.py file if not in repo or setuptools_scm is
+    # unavailable.
+    return _version.version
 
 
 @_api.caching_module_getattr

lib/matplotlib/_version.py.in

@@ -0,0 +1 @@
+version = @VCS_TAG@

lib/matplotlib/meson.build

@@ -138,6 +138,20 @@ typing_sources = [
 py3.install_sources(python_sources, typing_sources,
                     subdir: 'matplotlib')
 
+fs = import('fs')
+if fs.exists('_version.py')
+    py3.install_sources('_version.py', subdir: 'matplotlib')
+else
+  cfg = configuration_data()
+  cfg.set_quoted('VCS_TAG', meson.project_version())
+  configure_file(
+    input: '_version.py.in', output: '_version.py',
+    configuration: cfg,
+    install: true,
+    install_tag: 'python-runtime',
+    install_dir: py3.get_install_dir() / 'matplotlib')
+endif
+
 subdir('_api')
 subdir('axes')
 subdir('backends')