docs: add fork-budget rule with census method and measured limits by Chemaclass · Pull Request #812 · TypedDevs/bashunit

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.

Chemaclass · 2026-07-16T03:15:50Z

🤔 Background

The fork-reduction series (#801-#811) produced measurement techniques and — equally valuable — measured dead ends that would otherwise be re-discovered (or worse, "optimized" into regressions) by the next contributor or agent touching src/.

💡 Changes

New path-scoped rule .claude/rules/perf-fork-budget.md: shim-census method (and why bash -x counts are inflated), the replacement patterns that worked, where pure bash measurably loses to awk, and the current per-run fork budgets enforced by the regression tests.
Auto-loads when editing src/** so future perf work starts from evidence.

Records how PRs #801-#811 measured forks (PATH-shim census as ground truth; bash -x traces overcount via re-echoed test output), the replacement patterns that worked, and — equally important — the measured dead ends (bash loops lose to awk beyond ~100 lines, ${var//} is quadratic on bash 3.2, single-file build is not faster, tput width is snapshot-load-bearing). Auto-loads when editing src/ so future perf work starts from evidence instead of re-profiling.