pandoc server 3.9 errors on macOS

[lukaszcz]

System: macOS Sequoia 15.6

1. Install official macOS release binary for Pandoc 3.9 from GitHub
2. Start Pandoc server: pandoc server
3. Query:

curl -s http://127.0.0.1:3030/ \
     -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -d '{
       "text": "Hello World",
       "from": "markdown",
       "to": "html5"
     }'

3. Result:

GHC.Internal.Event.Thread.getSystemTimerManager: the TimerManager requires linking against the threaded runtime
CallStack (from HasCallStack):
  error, called at libraries/ghc-internal/src/GHC/Internal/Event/Thread.hs:290:13 in ghc-internal:GHC.Internal.Event.Thread

With version 3.8.3 I get correct output:

{"output":"<p>Hello World</p>","base64":false,"messages":[]}

[jgm]

I can reproduce this. There have been no changes in the pandoc-server library itself between 3.8.3 and 3.9. So, we should look at pandoc-cli. And I note that the -threaded option has been dropped from ghc-options. That is probably the issue.

[jgm]

Adding -threaded again didn't seem to fix the issue. Hm.

[jgm]

Since -threaded didn't make a difference, I don't know what the issue could be. There are no changes in the code that seem relevant to me. It's possible that there are changes in dependencies that could be affecting this.