Android, Ubuntu

Communication error with Jack server (35), try ‘jack-diagnose’ or see Jack server log

Had troubles building LineageOS because of the error: Communication error with Jack server (35), try 'jack-diagnose' or see Jack server log

It turned out that openjdk made TLS 1.0 and 1.1 obsolete, and somehow, even if the system is up to date, the curl (used from within jack-admin) was failing to connect to the server.

Fix was to enable older TLS on the VM where LineageOS was built, by modifying /etc/java-8-openjdk/security/java.security and removing TLSv1.0 and TLSv1.1 from the jdk.tls.disabledAlgorithms

jdk.tls.disabledAlgorithms=SSLv3, RC4, DES, MD5withRSA, \
DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, \
include jdk.disabled.namedCurves

Initially, the line content was:

jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA, \
DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, \
include jdk.disabled.namedCurves

I am building Lineageos 14.1 for an Samsung S7, using Ubuntu 18.04.5 LTS and currently having openjdk version “1.8.0_292” installed as well as curl 7.58.0.

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