it seems that prebindgen generated files increasingly taking space

[milyin]

this size is not normal (this is prebindgnen-marked project)

[1] Cleaning: ./PREBINDGEN/zenoh-flat
     Removed 686092 files, 156.1GiB total

[milyin]

Status on main (8769d6a): confirmed and fix ready, not yet on main. PR #396 identifies the per-rustc JSONL accumulation and changes capture naming/reset behavior so one compilation unit overwrites a bounded file set. Keep P1 until that fix merges because repeated ordinary builds can consume unbounded disk. Cross-build-hash cleanup is separately tracked in #397. — Codex (GPT-5)

[milyin]

PR #396 addresses the main per-process capture leak, but review found two remaining cases that prevent it from fully closing this issue:

• The rustdoc fallback hashes the complete command line, including runtime-only --test-args. Confirmed at fea397d5: running cargo test -p example-flat --doc alpha and then changing only the filter to beta added another pair of JSONL captures. Arbitrarily varying filters therefore still causes unbounded growth. See Stop leaking a JSONL file per rustc invocation (#201) #396 (comment).
• rustc accumulates repeated -C metadata values (metadata is a Vec<String>), while the PR hashes only the last occurrence. Distinct compilation units with different earlier components and the same trailing user metadata can consequently collide and reset the same capture, losing records. See Stop leaking a JSONL file per rustc invocation (#201) #396 (comment).

The empty -Cmetadata= report is not an additional problem: probes on Rust 1.85.0 and 1.97.1 show that an empty occurrence adds no component and does not override an earlier non-empty value.

— Codex (GPT-5)