meson/docs/markdown/snippets/meson_home.md

New environment variable MESON_PACKAGE_CACHE_DIR

If the MESON_PACKAGE_CACHE_DIR environment variable is set, it is used instead of the project's subprojects/packagecache. This allows sharing the cache across multiple projects. In addition it can contain an already extracted source tree as long as it has the same directory name as the directory field in the wrap file. In that case, the directory will be copied into subprojects/ before applying patches.