With --vverbose:

1st time:

$ dub --vverbose build
Using dub registry url 'http://code.dlang.org/'
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
Failed to run git: git rev-parse failed: fatal: Not a git repository: '/home/space/phujfj/Documents/DistD/.git'

Note: Failed to determine version of package distd at /home/space/phujfj/Documents/DistD. Assuming ~master.
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
Collecting dependencies for distd
Found dependency zmqd ~master: false
Checking dependencies in '/home/space/phujfj/Documents/DistD'
Try to resolve ["zmqd"]
There are 1 packages missing.
Adding package to graph: zmqd
Fetching package zmqd (1 suppliers registered)
Downloading metadata for zmqd
Getting from http://code.dlang.org/packages/zmqd.json
Getting http://code.dlang.org/packages/zmqd.json...
markUpToDate(zmqd)
writeDubJson
Try to resolve ["zeromq"]
There are 1 packages missing.
Adding package to graph: zeromq
Fetching package zeromq (1 suppliers registered)
Downloading metadata for zeromq
Getting from http://code.dlang.org/packages/zeromq.json
Getting http://code.dlang.org/packages/zeromq.json...
markUpToDate(zeromq)
writeDubJson
Triggering retrieval of required package 'zeromq', which was not present.
Triggering retrieval of required package 'zmqd', which was not present.
writeDubJson
The following changes will be performed:
Fetch zeromq ~master, userWide
Fetch zmqd ~master, userWide
Fetching zeromq ~master...
Acquiring package zip file
Found download URL: 'http://code.dlang.org/packages/zeromq/~master.zip'
Storing http://code.dlang.org/packages/zeromq/~master.zip...
Placing zeromq ~master to /home/space/phujfj/.dub/packages/...
Placing package 'zeromq' version '~master' to location '/home/space/phujfj/.dub/packages/zeromq-master' from file '/tmp/zeromq-master.zip'
Opening file /tmp/zeromq-master.zip
Extracting from zip.
zip root folder: ZeroMQ-master
Copying all files...
Creating AUTHORS
Creating C/
Creating C/zmq.h
Creating deimos/zmq/utils.d
Creating examples/README
Creating package.json
Creating deimos/zmq/zmq.d
Creating C/zmq_utils.h
Creating README
Creating deimos/
Creating examples/
Creating examples/hwclient.d
Creating examples/hwserver.d
Creating deimos/zmq/
10 file(s) copied.
Failed to run git: git rev-parse failed: fatal: Not a git repository: '/home/space/phujfj/.dub/packages/zeromq-master/.git'

Note: Failed to determine version of package ZeroMQ at /home/space/phujfj/.dub/packages/zeromq-master. Assuming ~master.
Saving retrieval action journal...
Fetching zmqd ~master...
Acquiring package zip file
Found download URL: 'http://code.dlang.org/packages/zmqd/~master.zip'
Storing http://code.dlang.org/packages/zmqd/~master.zip...
Placing zmqd ~master to /home/space/phujfj/.dub/packages/...
Placing package 'zmqd' version '~master' to location '/home/space/phujfj/.dub/packages/zmqd-master' from file '/tmp/zmqd-master.zip'
Opening file /tmp/zmqd-master.zip
Extracting from zip.
zip root folder: zmqd-master
Copying all files...
Creating LICENCE.txt
Creating examples/taskvent.d
Creating examples/msreader.d
Creating src/zmqd.d
Creating examples/README.txt
Creating examples/wuclient.d
Creating examples/
Creating examples/tasksink.d
Creating examples/hwclient.d
Creating README.md
Creating examples/wuserver.d
Creating package.json
Creating examples/zhelpers.d
Creating examples/taskwork.d
Creating examples/hwserver.d
Creating src/
14 file(s) copied.
Failed to run git: git rev-parse failed: fatal: Not a git repository: '/home/space/phujfj/.dub/packages/zmqd-master/.git'

Note: Failed to determine version of package zmqd at /home/space/phujfj/.dub/packages/zmqd-master. Assuming ~master.
Saving retrieval action journal...
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
iterating dir /home/space/phujfj/.dub/packages/
iterating dir /home/space/phujfj/.dub/packages/ entry zeromq-master
iterating dir /home/space/phujfj/.dub/packages/ entry zmqd-master
Collecting dependencies for distd
Found dependency zmqd ~master: true
Collecting dependencies for zmqd
Found dependency zeromq ~master: false
Try to resolve ["zmqd"]
There are 1 packages missing.
Adding package to graph: zmqd
Found present package zmqd ~master
Try to resolve ["zeromq"]
There are 1 packages missing.
Adding package to graph: zeromq
Fetching package zeromq (1 suppliers registered)
markUpToDate(zeromq)
writeDubJson
Triggering retrieval of required package 'zeromq', which was not present.
Required package 'zmqd' found with version '~master'
writeDubJson
Error executing command build: Unknown dependency: zeromq

Full exception: object.Exception@source/dub/project.d(141): Unknown dependency: zeromq
----------------
dub(const(int delegate(int delegate(ref const(dub.package_.Package))) function(bool, const(dub.package_.Package), immutable(char)[][immutable(char)[]])) dub.project.Project.getTopologicalPackageList.int iterator(int delegate(ref const(dub.package_.Package))).void perform_rec(const(dub.package_.Package)).int __foreachbody3(ref immutable(char)[], ref const(dub.dependency.Dependency))+0xb1) [0x61d025]
dub(_aaApply2+0x6a) [0x6dc53a]
dub(const(int delegate(int delegate(ref const(dub.package_.Package))) function(bool, const(dub.package_.Package), immutable(char)[][immutable(char)[]])) dub.project.Project.getTopologicalPackageList.int iterator(int delegate(ref const(dub.package_.Package))).void perform_rec(const(dub.package_.Package))+0x13d) [0x61cf11]
dub(const(int delegate(int delegate(ref const(dub.package_.Package))) function(bool, const(dub.package_.Package), immutable(char)[][immutable(char)[]])) dub.project.Project.getTopologicalPackageList.int iterator(int delegate(ref const(dub.package_.Package))).void perform_rec(const(dub.package_.Package)).int __foreachbody3(ref immutable(char)[], ref const(dub.dependency.Dependency))+0xca) [0x61d03e]
dub(_aaApply2+0x6a) [0x6dc53a]
dub(const(int delegate(int delegate(ref const(dub.package_.Package))) function(bool, const(dub.package_.Package), immutable(char)[][immutable(char)[]])) dub.project.Project.getTopologicalPackageList.int iterator(int delegate(ref const(dub.package_.Package))).void perform_rec(const(dub.package_.Package))+0x13d) [0x61cf11]
dub(const(int delegate(int delegate(ref const(dub.package_.Package))) function(bool, const(dub.package_.Package), immutable(char)[][immutable(char)[]])) dub.project.Project.getTopologicalPackageList.int iterator(int delegate(ref const(dub.package_.Package)))+0x64) [0x61cdc8]
dub(const(immutable(char)[][immutable(char)[]] function(const(dub.compilers.compiler.BuildPlatform), immutable(char)[], bool)) dub.project.Project.getPackageConfigs+0x1c2) [0x61de7e]
dub(const(immutable(char)[] function(dub.compilers.compiler.BuildPlatform, bool)) dub.project.Project.getDefaultConfiguration+0x7f) [0x61d26b]
dub(int dub.commandline.GenerateCommand.execute(dub.dub.Dub, immutable(char)[][], immutable(char)[][])+0x37a) [0x5f07c6]
dub(int dub.commandline.BuildCommand.execute(dub.dub.Dub, immutable(char)[][], immutable(char)[][])+0x8d) [0x5f0dd9]
dub(int dub.commandline.runDubCommandLine(immutable(char)[][])+0x11e8) [0x5eeb7c]
dub(_Dmain+0x20) [0x5ed34c]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll().void __lambda1()+0x18) [0x6dd734]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate())+0x2a) [0x6dd68e]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll()+0x30) [0x6dd6f4]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate())+0x2a) [0x6dd68e]
dub(_d_run_main+0x1a3) [0x6dd60f]
dub(main+0x25) [0x5ed991]
/lib64/libc.so.6(__libc_start_main+0xe6) [0x7f2a0c918c36]

2nd time:

$ dub --vverbose build
Using dub registry url 'http://code.dlang.org/'
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
iterating dir /home/space/phujfj/.dub/packages/
iterating dir /home/space/phujfj/.dub/packages/ entry zeromq-master
iterating dir /home/space/phujfj/.dub/packages/ entry zmqd-master
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
iterating dir /home/space/phujfj/.dub/packages/
iterating dir /home/space/phujfj/.dub/packages/ entry zeromq-master
iterating dir /home/space/phujfj/.dub/packages/ entry zmqd-master
Failed to run git: git rev-parse failed: fatal: Not a git repository: '/home/space/phujfj/Documents/DistD/.git'

Note: Failed to determine version of package distd at /home/space/phujfj/Documents/DistD. Assuming ~master.
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
iterating dir /home/space/phujfj/.dub/packages/
iterating dir /home/space/phujfj/.dub/packages/ entry zeromq-master
iterating dir /home/space/phujfj/.dub/packages/ entry zmqd-master
Looking for local package map at /var/lib/dub/packages/local-packages.json
Looking for local package map at /home/space/phujfj/.dub/packages/local-packages.json
iterating dir /home/space/phujfj/.dub/packages/
iterating dir /home/space/phujfj/.dub/packages/ entry zeromq-master
iterating dir /home/space/phujfj/.dub/packages/ entry zmqd-master
Collecting dependencies for distd
Found dependency zmqd ~master: true
Collecting dependencies for zmqd
Found dependency zeromq ~master: false
Checking dependencies in '/home/space/phujfj/Documents/DistD'
Try to resolve ["zmqd"]
There are 1 packages missing.
Adding package to graph: zmqd
Found present package zmqd ~master
Try to resolve ["zeromq"]
There are 1 packages missing.
Adding package to graph: zeromq
Fetching package zeromq (1 suppliers registered)
Downloading metadata for zeromq
Getting from http://code.dlang.org/packages/zeromq.json
Getting http://code.dlang.org/packages/zeromq.json...
markUpToDate(zeromq)
writeDubJson
Triggering retrieval of required package 'zeromq', which was not present.
Required package 'zmqd' found with version '~master'
writeDubJson
The following changes will be performed:
Fetch zeromq ~master, userWide
Fetching zeromq ~master...
Acquiring package zip file
Found download URL: 'http://code.dlang.org/packages/zeromq/~master.zip'
Storing http://code.dlang.org/packages/zeromq/~master.zip...
Placing zeromq ~master to /home/space/phujfj/.dub/packages/...
Placing package 'zeromq' version '~master' to location '/home/space/phujfj/.dub/packages/zeromq-master' from file '/tmp/zeromq-master.zip'
Error executing command build: zeromq (~master) needs to be removed from '/home/space/phujfj/.dub/packages/zeromq-master' prior placement.

Full exception: object.Exception@source/dub/packagemanager.d(212): zeromq (~master) needs to be removed from '/home/space/phujfj/.dub/packages/zeromq-master' prior placement.
----------------
dub(dub.package_.Package dub.dub.Dub.fetch(immutable(char)[], const(dub.dependency.Dependency), dub.project.PlacementLocation, bool, bool)+0x7af) [0x5fe56b]
dub(void dub.dub.Dub.update(dub.project.UpdateOptions)+0x4b6) [0x5fc952]
dub(void dub.commandline.PackageBuildCommand.setupPackage(dub.dub.Dub, immutable(char)[])+0x2f6) [0x5efb8a]
dub(int dub.commandline.GenerateCommand.execute(dub.dub.Dub, immutable(char)[][], immutable(char)[][])+0x1d7) [0x5f0623]
dub(int dub.commandline.BuildCommand.execute(dub.dub.Dub, immutable(char)[][], immutable(char)[][])+0x8d) [0x5f0dd9]
dub(int dub.commandline.runDubCommandLine(immutable(char)[][])+0x11e8) [0x5eeb7c]
dub(_Dmain+0x20) [0x5ed34c]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll().void __lambda1()+0x18) [0x6dd734]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate())+0x2a) [0x6dd68e]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).runAll()+0x30) [0x6dd6f4]
dub(void rt.dmain2._d_run_main(int, char**, extern (C) int function(char[][])*).tryExec(scope void delegate())+0x2a) [0x6dd68e]
dub(_d_run_main+0x1a3) [0x6dd60f]
dub(main+0x25) [0x5ed991]
/lib64/libc.so.6(__libc_start_main+0xe6) [0x7f179d9d7c36]