I keep running into weird issues when trying to install packages through npm on my Windows setup with Cygwin. The problem is really strange because it doesn’t happen every time. Sometimes a package will install just fine, but other times the exact same package fails with permission errors. I tried installing a text processing library and it failed about 4 times before it finally worked on the fifth attempt.
The error I keep getting looks like this:
npm ERR! Failed to extract /tmp/npm-temp-folder/package-archive.tgz
npm ERR! Error: EACCES, access denied '/tmp/npm-temp-folder/extracted-files/'
npm ERR!
npm ERR! Try running with 'sudo' or as administrator
npm ERR!
npm ERR! sudo npm install text-processor
npm ERR!
npm ERR! You can also try setting unsafe-perm to true
npm ERR!
npm ERR! npm config set unsafe-perm true
npm ERR!
npm ERR! System CYGWIN_NT-6.1 version info
npm ERR! command "node" "/usr/local/bin/npm" "install" "text-processor"
I already tried setting the unsafe-perm setting to true but it doesn’t help. This happens with basically every package I try to install. Has anyone dealt with this before and found a fix?
I had this exact same problem when I was working on a Node.js project last year. The intermittent nature of the failures drove me crazy for weeks. What eventually fixed it for me was changing the npm temp directory location away from the default /tmp path that Cygwin uses. Run npm config set tmp C:\temp to point npm to a Windows-native temp directory instead of the Cygwin one. Also make sure to run npm config set cache C:\npm-cache to move the cache to a proper Windows path. The issue stems from Cygwin’s virtual filesystem layer conflicting with npm’s file operations, especially when multiple processes try to access the same temp files simultaneously. After making these changes, my package installations became much more reliable. You might also want to check if any antivirus software is interfering with the temp folder access, as that can cause similar random permission denials.
This is a common issue with Cygwin’s handling of Windows file permissions and symlinks. I encountered similar random failures when I was using Cygwin for development work. The root cause is usually related to how Cygwin translates Unix-style permissions to Windows ACLs, which can create race conditions during package extraction. What solved it for me was switching to use npm through Windows Command Prompt or PowerShell instead of the Cygwin terminal. You can still keep your Cygwin environment for other tasks, but run npm commands directly in a Windows shell. The Windows version of Node.js handles file permissions much more reliably than trying to bridge through Cygwin’s POSIX layer. Alternatively, if you need to stick with Cygwin, try clearing the npm cache completely with npm cache clean --force before installing packages. Sometimes corrupted cache entries can trigger these permission conflicts.
sounds like windows defender or antivirus might be scanning files during extraction. try adding your node_modules and npm temp folders to the exclusion list in windows security settings. this fixed my random npm fails completly