Segmentation fault when a server is already running

[scivola]

versions

• macOS 26.2
• ruby 4.0.1 (2026-01-13 revision e04267a14b) +PRISM [arm64-darwin25]
• Rails 8.1.2
• dartsass-rails (0.5.1)

reproduction

rails new test1 -c sass
cd test1
bin/dev

Then at another terminal (the same directory):

bin/dev

log

03:26:04 web.1  | started with pid 94429
03:26:04 css.1  | started with pid 94430
03:26:05 web.1  | => Booting Puma
03:26:05 web.1  | => Rails 8.1.2 application starting in development 
03:26:05 web.1  | => Run `bin/rails server --help` for more startup options
03:26:05 web.1  | A server is already running (pid: 93764, file: /Users/XXXXX/temp/test1/tmp/pids/server.pid).
03:26:05 web.1  | Exiting
03:26:05 css.1  | Sass is watching for changes. Press Ctrl-C to stop.
03:26:05 css.1  | 
03:26:05 web.1  | exited with code 1
03:26:05 system | sending SIGTERM to all processes
03:26:05 css.1  | /Users/XXXXX/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/gems/dartsass-rails-0.5.1/lib/tasks/build.rake:11: [BUG] Segmentation fault at 0x000000000000001f
03:26:05 css.1  | ruby 4.0.1 (2026-01-13 revision e04267a14b) +PRISM [arm64-darwin25]
03:26:05 css.1  | 
03:26:05 css.1  | -- Crash Report log information --------------------------------------------
03:26:05 css.1  |    See Crash Report log file in one of the following locations:
03:26:05 css.1  |      * ~/Library/Logs/DiagnosticReports
03:26:05 css.1  |      * /Library/Logs/DiagnosticReports
03:26:05 css.1  |    for more details.
03:26:05 css.1  | Don't forget to include the above Crash Report log file in bug reports.
03:26:05 css.1  | 
03:26:05 css.1  | -- Control frame information -----------------------------------------------
03:26:05 css.1  | c:0032 p:---- s:0200 e:000199 l:y b:---- CFUNC  :system
03:26:05 css.1  | c:0031 p:0015 s:0161 e:000160 l:n b:---- BLOCK  /Users/XXXXX/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/gems/dartsass-rails-0.5.1/lib/tasks/build.rake:11
03:26:05 css.1  | c:0030 p:0007 s:0158 e:000157 l:n b:---- BLOCK  /Users/XXXXX/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/gems/rake-13.3.1/lib/rake/task.rb:281 [FINISH]
03:26:05 css.1  | c:0029 p:---- s:0154 e:000153 l:y b:---- CFUNC  :each
03:26:05 css.1  | c:0028 p:0113 s:0150 e:000149 l:y b:0001 METHOD /Users/XXXXX/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/gems/rake-13.3.1/lib/rake/task.rb:281
03:26:05 css.1  | c:0027 p:0117 s:0144 e:000143 l:n b:---- BLOCK  /Users/XXXXX/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/gems/rake-13.3.1/lib/rake/task.rb:219 [FINISH]

The full-text is log.txt.

[andsmedeiros]

I can confirm this in a Docker setup (image: ruby:4.0.1-alpine, same version of everything), but it happens whenever the container is teared down, even if everything was running correctly before (i.e. no stray processes).

store     | 14:20:16 system | SIGTERM received, starting shutdown
store     | 14:20:17 system | sending SIGTERM to all processes
store     | 14:20:17 css.1  | /usr/local/bundle/gems/dartsass-rails-0.5.1/lib/tasks/build.rake:11: [BUG] Segmentation fault at 0x000000000000001f
store     | 14:20:17 web.1  | - Gracefully stopping, waiting for requests to finish
store     | 14:20:17 css.1  | ruby 4.0.1 (2026-01-13 revision e04267a14b) +PRISM [x86_64-linux-musl]
store     | 14:20:17 css.1  | 
store     | 14:20:17 css.1  | -- Control frame information -----------------------------------------------
store     | 14:20:17 css.1  | c:0032 p:---- s:0202 e:000201 l:y b:---- CFUNC  :system
store     | 14:20:17 css.1  | c:0031 p:0015 s:0161 e:000160 l:n b:---- BLOCK  /usr/local/bundle/gems/dartsass-rails-0.5.1/lib/tasks/build.rake:11
store     | 14:20:17 css.1  | c:0030 p:0007 s:0158 e:000157 l:n b:---- BLOCK  /usr/local/lib/ruby/gems/4.0.0/gems/rake-13.3.1/lib/rake/task.rb:281 [FINISH]
store     | 14:20:17 css.1  | c:0029 p:---- s:0154 e:000153 l:y b:---- CFUNC  :each
store     | 14:20:17 web.1  | Exiting