build.properties

# Property files contain key/value pairs
key=value

# Property keys may contain alphanumeric chars and colons, but
# not special chars. This way you can create pseudo-namespaces
umil.repository=git://github.com/phpbb/umil.git
umil.version=v1.0.5
umil.directory=${temp.dir}/umil

build.xml

<?xml version="1.0"  encoding="UTF-8" ?>
<project name="phpbb3-nv-who-was-here" basedir="." default="umil">
  <property name="temp.dir" value="temp" />
	<property name="build.dir" value="build" />

	<property file="build.properties" />

	<target name="clean" description="Remove build directories">
		<echo msg="Remove build directories" />
		<delete dir="${build.dir}" />
		<delete dir="${temp.dir}/umil" includeemptydirs="true" verbose="true" />
	</target>

	<target name="prepare" depends="clean" description="Prepare packaging">
		<echo msg="Creating directories" />
		<mkdir dir="${build.dir}" />
		<mkdir dir="${temp.dir}" />
	</target>

	<target name="umil" depends="clean,prepare" description="Download phpBB/UMIL">
		<echo msg="Download phpBB/UMIL" />
		<gitclone gitPath="git" repository="${umil.repository}" targetPath="${umil.directory}" />
		<gitcheckout gitPath="git" repository="${umil.directory}" branchname="${umil.version}" quiet="true" create="true" />
	</target>
</project>

gistfile1.txt

Buildfile: E:\Extensions\htdocs\who-was-here\git\build.xml
 [property] Loading E:\Extensions\htdocs\who-was-here\git\build.properties

phpbb3-nv-who-was-here > clean:

     [echo] Remove build directories
   [delete] Directory E:\Extensions\htdocs\who-was-here\git\build does not exist
 or is not a directory.
   [delete] Deleting E:\Extensions\htdocs\who-was-here\git\temp\umil\.git\object
s\pack\pack-7682ab46f76bde9efc783d8c4ac37288d0f6c82f.idx
   [delete] Unable to delete file E:\Extensions\htdocs\who-was-here\git\temp\umi
l\.git\objects\pack\pack-7682ab46f76bde9efc783d8c4ac37288d0f6c82f.idx: FileSyste
m::unlink() FAILED. Cannot unlink 'E:\Extensions\htdocs\who-was-here\git\temp\um
il\.git\objects\pack\pack-7682ab46f76bde9efc783d8c4ac37288d0f6c82f.idx'.
   [delete] Deleting E:\Extensions\htdocs\who-was-here\git\temp\umil\.git\object
s\pack\pack-7682ab46f76bde9efc783d8c4ac37288d0f6c82f.pack
   [delete] Unable to delete file E:\Extensions\htdocs\who-was-here\git\temp\umi
l\.git\objects\pack\pack-7682ab46f76bde9efc783d8c4ac37288d0f6c82f.pack: FileSyst
em::unlink() FAILED. Cannot unlink 'E:\Extensions\htdocs\who-was-here\git\temp\u
mil\.git\objects\pack\pack-7682ab46f76bde9efc783d8c4ac37288d0f6c82f.pack'.
   [delete] Deleting directory E:\Extensions\htdocs\who-was-here\git\temp\umil\.
git\objects\pack
   [delete] Unable to delete directory E:\Extensions\htdocs\who-was-here\git\tem
p\umil\.git\objects\pack: FileSystem::rmdir() FAILED. Cannot rmdir E:\Extensions
\htdocs\who-was-here\git\temp\umil\.git\objects\pack.
   [delete] Deleting directory E:\Extensions\htdocs\who-was-here\git\temp\umil\.
git\objects
   [delete] Unable to delete directory E:\Extensions\htdocs\who-was-here\git\tem
p\umil\.git\objects: FileSystem::rmdir() FAILED. Cannot rmdir E:\Extensions\htdo
cs\who-was-here\git\temp\umil\.git\objects.
   [delete] Deleting directory E:\Extensions\htdocs\who-was-here\git\temp\umil\.
git
   [delete] Unable to delete directory E:\Extensions\htdocs\who-was-here\git\tem
p\umil\.git: FileSystem::rmdir() FAILED. Cannot rmdir E:\Extensions\htdocs\who-w
as-here\git\temp\umil\.git.
   [delete] Deleting directory E:\Extensions\htdocs\who-was-here\git\temp\umil
   [delete] Unable to delete directory E:\Extensions\htdocs\who-was-here\git\tem
p\umil: FileSystem::rmdir() FAILED. Cannot rmdir E:\Extensions\htdocs\who-was-he
re\git\temp\umil.

phpbb3-nv-who-was-here > prepare:

     [echo] Creating directories
    [mkdir] Created dir: E:\Extensions\htdocs\who-was-here\git\build

phpbb3-nv-who-was-here > umil:

     [echo] Download phpBB/UMIL
Execution of target "umil" failed for the following reason: E:\Extensions\htdocs
\who-was-here\git\build.xml:22:42: "temp/umil" target directory is not empty

BUILD FAILED
E:\Extensions\htdocs\who-was-here\git\build.xml:22:42: "temp/umil" target direct
ory is not empty
Total time: 0.2968 seconds