Bun Startup Time Scales Excessively with Large Directories in CWD or Ancestor Paths
- Investigating(current)
- Trending(upcoming)
- Workaround available(upcoming)
- Resolved(upcoming)
Executive summary
Bun startup performance degrades significantly when executed in or beneath directories containing large numbers of entries. The issue affects macOS (Darwin arm64) users on versions 1.4.2 through 1.4.4 and higher.
No verified workaround yet
None of the linked reports describe a mitigation. Follow this incident to hear when one appears.
Under active investigation. No report has identified a root cause yet.
Evidence
1 report · 1 GitHubShow
- [1]GitHub First reportStartup time scales with the number of entries in the cwd and every ancestor directory(opens GitHub issue in a new tab)
What version of Bun is running? 1.4.4+38afee6c8 (also reproduces on 1.4.2+744846f84) What platform is your computer? Darwin 25.6.0 arm64 arm What steps can reproduce the bug? mkdir -p /tmp/bun-bigdir/sub && cd /tmp/bun-bigdir node -e 'const fs=require("fs");for(let i=0;i<200000;i++)fs.writeFileSync("f"+i,"")' mkdir -p /tmp/bun-empty median of 7 runs each cd /tmp/bun-empty && time bun -e 0 cd /tmp/bun-bigdir && time bun -e 0 cd /tmp/bun-bigdir/sub && time bun -e 0 # the big dir is only an…
by johnny4young 0upvotes 1comments
Timeline
- First report on GitHub issue
Startup time scales with the number of entries in the cwd and every ancestor directory
Source