[Logic769]

Problem

env -a foo (or --argv0 foo) without a command printed the environment instead of failing. GNU env requires a command when --argv0 is given.

Change

Return a usage error (exit 125) when --argv0 is set but no command follows, with a clear message, and add regression tests.

Closes #15991

[codspeed]

Merging this PR will improve performance by 14.18%

1 warning, 1 note

⚠️ 122 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

ℹ️ 1 benchmark has no flamegraph

The flamegraph wasn't generated: most of the time was spent in runtime internals, which would leave nothing useful to analyze.

See affected benchmarks

⚡ 2 improved benchmarks
✅ 399 untouched benchmarks
⏩ 70 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	CPU Simulation	mv_force_overwrite	154.4 ms	128.1 ms	+20.56%
⚡	CPU Simulation	sort_long_line[10000]	1,078.2 µs	997 µs	+8.15%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing Logic769:env-argv0-requires-command (b2e5610) with main (9cc868b)}

Footnotes

1. 70 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩