Measured here (Isabelle2025-2, one thread): HOL-Library from scratch takes ~11 minutes and peaks at ~5.3 GiB -- what nightly 174 was killed doing; the StarForth session on a built HOL-Library takes under a minute and ~2.2 GiB. The image builds HOL-Library once into Isabelle's own heaps, so every job finds it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GE3SDvQn5EoxdGufk84zz2