BLD: optimize sdist contents through a dist script

.gitattributes

@@ -3,6 +3,11 @@
 
 # Note: when adding to this list, be aware that you need to commit your changes
 # before they take effect (can be confusing during testing)
+#
+# Note: git submodules cannot be handled in this file. For removing
+# files and directories from git submodules, see `tools/trim_sdist_content.py`
+# This is a Meson "dist script", run during sdist generation only.
+
 .circleci/* export-ignore
 .github/* export-ignore
 ci/* export-ignore

meson.build

@@ -14,6 +14,8 @@ project(
   ],
 )
 
+meson.add_dist_script('tools/trim_sdist_content.py')
+
 py3 = import('python').find_installation(pure: false)
 py3_dep = py3.dependency()
 

tools/trim_sdist_content.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+"""
+The purpose of this script is to remove files from the sdist that are not
+needed and bloat the sdist size too much. This deals with files from
+git submodules, because those cannot be removed by using `export-ignore`
+in the top-level `.gitattributes` file.
+"""
+
+import os
+import pathlib
+import shutil
+
+dist_root = pathlib.Path(os.environ['MESON_DIST_ROOT'])
+
+for name in [dist_root / d for d in (
+    'subprojects/boost_math/math/.github',
+    'subprojects/boost_math/math/build',
+    'subprojects/boost_math/math/config',
+    'subprojects/boost_math/math/doc',
+    'subprojects/boost_math/math/example',
+    'subprojects/boost_math/math/meta',
+    'subprojects/boost_math/math/reporting',
+    'subprojects/boost_math/math/src',
+    'subprojects/boost_math/math/test',
+    'subprojects/boost_math/math/tools',
+    'subprojects/highs/.github',
+    'subprojects/highs/app',
+    'subprojects/highs/check',
+    'subprojects/highs/docs',
+    'subprojects/highs/examples',
+    'subprojects/highs/nuget',
+    'subprojects/highs/scripts',
+    'subprojects/highs/tests',
+    'subprojects/xsf/.github',
+    'subprojects/xsf/pixi.lock',
+    'subprojects/xsf/tests',
+    )]:
+    if name.is_file():
+        name.unlink()
+    else:
+        shutil.rmtree(name)
+