remotetea version 1.0.7-2 failed to build with openjdk-7

During a rebuild test on precise with default-jdk switched to openjdk-7, a build failure was detected for remotetea version 1.0.7-2.

See attached log for full build failure details.

This log snippet might also be of interest:

dpkg-buildpackage: source package remotetea
dpkg-buildpackage: source version 1.0.7-2
dpkg-buildpackage: source changed by Picca Frédéric-Emmanuel <email address hidden>
 dpkg-source --before-build remotetea-1.0.7
dpkg-buildpackage: host architecture amd64
 fakeroot debian/rules clean
dh --with javahelper clean
   dh_testdir
   dh_auto_clean
Buildfile: /«PKGBUILDDIR»/build.xml

clean:

BUILD SUCCESSFUL
Total time: 0 seconds
   jh_clean
   dh_clean
 debian/rules build
dh --with javahelper build
   dh_testdir
   dh_auto_configure
   jh_linkjars
   debian/rules override_dh_auto_build
make[1]: Entering directory `/«PKGBUILDDIR»'
ant jar javadoc
Buildfile: /«PKGBUILDDIR»/build.xml

compile:
    [mkdir] Created dir: /«PKGBUILDDIR»/classes
    [javac] /«PKGBUILDDIR»/build.xml:23: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
    [javac] Compiling 130 source files to /«PKGBUILDDIR»/classes
    [javac] /«PKGBUILDDIR»/src/org/acplt/oncrpc/OncRpcUdpClient.java:255: error: unmappable character for encoding ASCII
    [javac] // infinite (??$@%&!!!) we need to ensure that we
    [javac] ^
    [javac] 1 error

BUILD FAILED
/«PKGBUILDDIR»/build.xml:23: Compile failed; see the compiler error output for details.

Total time: 2 seconds
make[1]: *** [override_dh_auto_build] Error 1
make[1]: Leaving directory `/«PKGBUILDDIR»'
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
────────────────────────────────────────────────────────────────────────────────
Build finished at 20111110-1619

Finished
────────

E: Build failure (dpkg-buildpackage died)