Issue2651

Recently I have noticed quite a few Travis CI builds failing with this error: *** buffer overflow detected ***: /usr/lib/jvm/java-7-openjdk-amd64/bin/java

An example is: https://travis-ci.org/jythontools/jython/jobs/313613197#L728

This only seems to be affecting openjdk7 builds.

Attached the Travis output log.

Still happening periodically. As before, failure happens in test_builtin.

Have just run a test locally on windows on open JDK 7 without seeing a failure. May be Linux build specific. 

Test run:

REM Try to reproduce test_builtin crash on JDK 7

FOR /L %%A IN (1,1,200) DO (
    echo %%A
    dist\bin\jython.exe  -m test.regrtest --verbose  test_grammar test_opcodes test_dict test_builtin
)

== 2.7.2a1+ (, May 24 2019, 14:21:32)
== [OpenJDK Client VM (Oracle Corporation)]
== platform: java1.7.0_75
== encodings: stdin=cp850, stdout=cp850, FS=utf-8
== locale: default=('en_AU', 'windows-1252'), actual=(None, None)

1.7.0_75 was the latest binary I could find in the openjdk7 windows series.

PR https://github.com/jythontools/jython/pull/145

In both the recent
https://travis-ci.org/jythontools/jython/jobs/535576706

and original 

https://travis-ci.org/jythontools/jython/jobs/313613197#L728

we see: 

/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/libnet.so(Java_java_net_Inet4AddressImpl_getLocalHostName+0x1a5)

which suggests 
https://github.com/travis-ci/travis-ci/issues/5227

... is the culprit. Also, the FTP job failure shows the following:
0.00s$ hostname
travis-job-f506d6d7-075f-46e9-a40c-7245b966dcae

... which is pretty long.

The recommended fix is to use the hosts addon 
https://docs.travis-ci.com/user/hosts/

Darjus applied an early workaround to the travis config in c547fb5b96eaab78f0a8030a50f33ae68da85f04, but there is now a more standard one available, and maybe the old one doesn't work any more. Hence the PR above.

Fixed at https://hg.python.org/jython/rev/ef7b8771ce6d