Dmd nightly was last successfully built on November 1. Since then, building halts with an access violation. https://nightlies.dlang.org/dmd-master-2017-11-02/build.html

Entering dir: clones\dlang.org
Running: make MODEL=32 DMD=..\dmd\src\dmd HOST_DC=C:\Users\vagrant\old-dmd\dmd2\windows\bin\dmd.exe RELEASE=1 LATEST=master -f win32.mak chm
..\dmd\src\dmd -g chmgen

..\dmd\src\dmd -run modlist.d ..\druntime ..\phobos --ex=gc. --ex=rt. --ex=core.internal. --ex=core.stdc.config --ex=core.sys.  --ex=std.c. --ex=std.algorithm.internal --ex=std.internal. --ex=std.regex.internal.  --ex=std.typelist --ex=std.windows. --ex=etc.linux.memoryerror  --ex=std.stream --ex=std.cstream --ex=socketstream  --ex=std.experimental.ndslice.internal >modlist-release.ddoc
..\dmd\src\dmd -o- -c -Dfchm-nav.json macros.ddoc html.ddoc dlang.org.ddoc windows.ddoc doc.ddoc std.ddoc spec\spec.ddoc modlist-release.ddoc changelog\changelog.ddoc chm-nav.dd 

..\dmd\src\dmd -o- -c -D macros.ddoc html.ddoc dlang.org.ddoc windows.ddoc doc.ddoc  cppcontracts.dd

object.Error@(0): Access Violation
----------------
0x006530B6
0x00473974
0x0046AE3D
0x00524FF0
0x005266E6
0x0065B5DF
0x0065B4E0
0x0052A768
0x76AA33CA in BaseThreadInitThunk
0x77199ED2 in RtlInitializeExceptionChain
0x77199EA5 in RtlInitializeExceptionChain

--- errorlevel 1
create_dmd_release: Error: Command failed (ran from dir 'clones\dlang.org'): make MODEL=32 DMD=..\dmd\src\dmd HOST_DC=C:\Users\vagrant\old-dmd\dmd2\windows\bin\dmd.exe RELEASE=1 LATEST=master -f win32.mak chm
Entering dir: C:\Users\vagrant
==> default: Forcing shutdown of VM...
==> default: Destroying VM and associated drives...
object.Exception@build_all.d(78): Enforcement failed
----------------
??:? pure @safe void std.exception.bailOut!(Exception).bailOut(immutable(char)[], ulong, const(char[])) [0x557677]
??:? pure @safe bool std.exception.enforce!(Exception, bool).enforce(bool, lazy const(char)[], immutable(char)[], ulong) [0x5575f4]
??:? void build_all.Shell.__dtor() [0x543539]
??:? void build_all.Shell.__aggrDtor() [0x543578]
??:? void build_all.runBuild(ref build_all.Box, immutable(char)[], bool, bool) [0x5450cc]
??:? void build_all.Box.build(immutable(char)[], bool, bool) [0x543dd8]
??:? _Dmain [0x549618]
??:? _D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv [0x5992be]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [0x599214]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll() [0x59927a]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate()) [0x599214]
??:? _d_run_main [0x599171]
??:? main [0x592945]
??:? __libc_start_main [0x1ea9ab14]