macOS 11 and later ship system libraries only inside the dyld shared
cache. trace_dylib_resolution therefore left every /usr/lib and /System
load undetermined, and REA had no way to see what a cache contains.
inspect_dyld_shared_cache (CLI inspect-dyld-shared-cache) reads a cache
file set selected by path, without an open target. Its pure TypeScript
reader parses modern and legacy dyld_cache_header layouts and reports:
- UUID, architecture, platform, OS version, Mac Catalyst alternate,
cache type, shared region, max slide;
- every VM mapping;
- each subcache by file suffix, checked by UUID. A missing or
mismatched subcache makes coverage partial;
- the complete image list.
For each requested install path it reads that image's load commands
through the cache mappings with the existing Mach-O reader.
trace_dylib_resolution accepts an optional shared_cache. Absolute
candidates found in a cache that serves the process's CPU family resolve
with the new outcome and status `shared-cache`. That status also takes
precedence over later in-bundle fallbacks such as a back-deployed
libswiftCore. The result names the cache UUID and OS version it used.
verify:dyld-shared-cache checks every image in the host cache (3,649 on
macOS 26.6), with dependencies and their re-export, weak, upward and
delay-init attributes, against `dyld_info -all_dyld_cache
-linked_dylibs`. It also checks CLI/MCP parity, and that each
shared-cache edge in the fixture trace is a library dyld actually loads.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
