.travis.yml

language: d

install:
  - DMD_VERSION=2.062
  - wget http://ftp.digitalmars.com/dmd.${DMD_VERSION}.zip
  - unzip dmd.${DMD_VERSION}.zip

script:
  - DMD=./dmd2/linux/bin64/dmd MODEL=64 make -f posix.mak unittest

branches:
  only:
    - master

script depends on your build system. Travis CI uses 64bit environment, so you should use 64bit code generation.

Makefile

Sample Makefile for above use-case. Use ?= instead of = to assign variable from command line.

# build mode: 32bit or 64bit
MODEL ?= $(shell getconf LONG_BIT)
DMD ?= dmd
NAMES = foo
FILES = $(addsuffix .d, $(NAMES))
SRCS  = $(addprefix src/, $(FILES))
LIB = libfoo.a
DFLAGS = -Isrc -m$(MODEL) -w -d -property -O -release -nofloat -inline

target: $(LIB)

$(LIB):
	$(DMD) $(DFLAGS) -lib -of$(LIB) $(SRCS)

MAIN_FILE = "empty_foo_unittest.d"

unittest:
	echo 'import foo; void main(){}' > $(MAIN_FILE)
	$(DMD) $(DFLAGS) -unittest -of$(LIB) $(SRCS) -run $(MAIN_FILE)
	rm $(MAIN_FILE)