icewm: libc: failed to connect to tombstoned: No such file or directory

Getting this during build of icewm:

https://github.com/dosemu2/dosemu2/actions/runs/16538452368/job/46776548489
```
libc: Limited by the size of pthread_mutex_t, 32 bit bionic libc only accepts pid <= 65535, but current pid is 77037
libc: failed to connect to tombstoned: No such file or directory
make[2]: *** [Makefile:2200: preferences] Error 255
```

What can that be?
2 days ago it was fine.