syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Environment variables accessed during the build and their values when they exist.
context_before:     pub symbol_gallery: SymbolGallery,
context_after:     pub env_depinfo: Lock<FxIndexSet<(Symbol, Option<Symbol>)>>,