https://issues.dlang.org/show_bug.cgi?id=4890
badlink <andrea.9...@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution|--- |FIXED --- Comment #35 from badlink <andrea.9...@gmail.com> --- I took my time and started digging trough the druntime source to find the problem. I discovered that core.thread.suspend() sends SIGUSR1 to the thread to suspend so I launched GDB and tried to catch the signal but GDB never caught it. I couldn't explain that behavior so I googled "linux sigusr1 not sent" and Bam! --> https://bbs.archlinux.org/viewtopic.php?id=181142 The people on there already figured that it's a bug in the Gnome Display Manager which blocks SIGUSR1 for all child applications ! The bug is present in the current package gdm-3.12.2-1 which I am using and is causing this nasty deadlock in the D garbage collector. As a quick test I tried to run the testcase in a tty and it worked as expected. Hopefully the problem will solve itself in the next gdm update. --