Try build dfmt with ldc2, "dub" or "dub -b release" never finished.
alost 1 hour and never return.
Try with dmd2 get this error:
Running pre-generate commands for dfmt...
ld: in /opt/tools/dmd2/osx/lib/libphobos2.a(object_12_612.o), section __DATA/__thread_bss has type zero-fill but non-zero file offset for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Error: linker exited with status 1
uncaught exception
object.Exception@source/dub/internal/utils.d(218): Command failed with exit code 1: rdmd "/opt/tools/dfmt/dubhash.d"
??:? pure @safe bool std.exception.enforce!().enforce!(bool).enforce(bool, lazy const(char)[], immutable(char)[], ulong) [0x10247cb1a]
??:? void dub.internal.utils.runCommands(in immutable(char)[][], immutable(char)[][immutable(char)[]], immutable(char)[]) [0x10221ec4a]
??:? void dub.generators.generator.runBuildCommands(in immutable(char)[][], in dub.package_.Package, in dub.project.Project, in dub.generators.generator.GeneratorSettings, in dub.compilers.buildsettings.BuildSettings, in immutable(char)[][immutable(char)[]][]) [0x102280d74]
??:? int dub.generators.generator.ProjectGenerator.generate(dub.generators.generator.GeneratorSettings)._foreachbody8(ref dub.package.Package) [0x102276e9b]
Abort trap: 6