gr

gr - instant go run

gr is a drop-in replacement for go run with the following improvements:

• preserves the exit code of the executed tool,
• caches built binaries, so that repeated runs are instantaneous.

Limitations (not yet resolved):

• works only on packages, not on individual files,
• supports only Linux and macOS.

Usage

From this repository

Place the gr script into your $PATH, and make it executable. On first run, it will download, and cache a fixed version of gr, and then execute it.

Ajustable settings can be found in the script.

Monorepo

There is no ready-made recipe. Copy gr source code into the monorepo and create a script that checks whether it has been updated by comparison file mtimes.

Performance

Although Go started caching link results for go run and go tool in version 1.24, it still does a remarkably poor job. Benchmarks on a Mac M1 Max (macOS 15.2):

% hyperfine --warmup=100 -i 'go tool drozd' 'gr ./tools/drozd'
Benchmark 1: go tool drozd
  Time (mean ± σ):     187.0 ms ±   4.8 ms    [User: 261.7 ms, System: 952.7 ms]
  Range (min … max):   176.6 ms … 195.4 ms    16 runs

Benchmark 2: gr ./tools/drozd
  Time (mean ± σ):      14.4 ms ±   1.6 ms    [User: 7.9 ms, System: 5.2 ms]
  Range (min … max):    13.5 ms …  32.5 ms    168 runs

Summary
  gr ./tools/drozd ran
   12.97 ± 1.47 times faster than go tool drozd

Legal

Copyright Mikhail Gusarov [email protected].

Licensed under the terms of the Apache 2.0 license (see LICENSE-2.0.txt).