syntax_data: {"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"tcx.def_span(def.did()),"}]}
source_snippet:                         tcx.def_span(def.did()),
context_before:                     let guar = tcx.dcx().span_delayed_bug(
context_after:                         "union cannot be packed and aligned",