Function set_resolve_workers_default 

pub fn set_resolve_workers_default(workers: usize)

Set the process-wide default resolver width for every resolve started AFTER this call (an explicit crate::arms::ENV_RESOLVE_WORKERS still wins). 0 restores one per core. The twin of crate::arms::set_graph_cache_default, for an embedder that learns its role at runtime and cannot set the environment — edition 2024 makes set_var unsafe, and gunnar forbids unsafe. MEASURED (gunnar twin_snapshot_memory.rs, 2026-09-15): one worker per core, each inflating a whole blob, is +133 MiB of RssAnon for a 512 MiB snapshot install on a many-core box; two workers with a 16 MiB lookahead is +36 MiB, under gunnar’s 64 MiB twin ceiling.