Swift 6.2（Ubuntu 24.04 Linux环境）Swift Package Manager增量构建挂起问题求助

I’ve run into exactly this issue on Ubuntu 24.04 with Swift 6.2, and after digging through community discussions and testing various workarounds, here are some practical solutions that are way more efficient than your current full-reset approach:

Immediate Workarounds (No Full Reset Needed) #

• Disable Incremental Compilation Entirely
  The most reliable fix right now is to force SwiftPM to skip incremental builds using an environment variable. This avoids the broken planning stage entirely:

  SWIFTCI_USE_INCREMENTAL_BUILD=NO swift build
  

  To make this permanent so you don’t have to type it every time, add it to your shell config:

  echo 'export SWIFTCI_USE_INCREMENTAL_BUILD=NO' >> ~/.bashrc
  source ~/.bashrc
  

  Unlike your full-reset method, this keeps your build cache intact—you’ll just do a full compile each time, which is still way faster than purging everything (usually 10-15 seconds instead of 30-40).

• Use a Temporary Build Directory
  If you need to keep incremental builds for some cases but hit the hang, specify a fresh build directory to bypass cached state:

  swift build --build-path /tmp/swift-temp-build
  

  This creates a new build environment each time, so there’s no incremental logic to hang on.

Longer-Term Fixes #

• Official Patch Availability
  The SwiftPM team has already merged a fix for this exact issue into the main branch. If you’re comfortable using a development build, you can compile Swift from source to get the patched version. Alternatively, keep an eye out for the Swift 6.2.1 patch release, which should include the fix.

• Adjust Linux Inotify Limits
  Some users have reported that increasing inotify watch limits resolves the hang, since SwiftPM relies on inotify to track file changes for incremental builds. Try updating these system settings:

  echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
  sudo sysctl -p
  

  This raises the number of files a user can monitor, which might fix a deadlock caused by exhausted watch slots.

Why This Beats Your Current Temporary Solution #

Your current full-reset workflow works, but it wipes out all cached build artifacts every time. The SWIFTCI_USE_INCREMENTAL_BUILD=NO approach keeps your cache—you just skip the incremental planning step that’s hanging. This cuts down build time significantly while avoiding the hang entirely.

内容的提问来源于stack exchange，提问作者flyer2001