MKCL 1.1.9 is now available for general use. For the most part it is a compilation of minor bug fixes along with one notable sub-component upgrade, i.e.: the GC has been upgraded from bdwgc 7.2c to bdwgc 7.4 in hope it will be a better fit for the upcoming ARM/iOS/Android ports.
One relevant change in the GC configuration happened on all MS-Windows versions where it is now hard configured to avoid the use of function SignalObjectAndWait since Microsoft has reneged on its promise of atomic behavior. If you observe a deadlock of MKCL 1.1.8 or earlier on MS-Windows 7 or later this would be a possible cause. You should then either upgrade to MKCL 1.1.9 or later, or set the environment variable MK_GC_MARKERS to 0 in order to prevent parallel marking and its use of SignalObjectAndWait.
I hope that MKCL 1.1.9 will be the last in the MKCL 1.1.X line before the release of MKCL 1.2.0 in the coming months.