Failing builds - sudo or dpkg

Although it builds fine for me locally, the build server yields: https://f-droid.org/wiki/page/org.telegram.messenger/lastbuild_11565

== Installed Android Tools ==

INFO: Creating log directory
INFO: Creating temporary directory
INFO: Creating output directory
INFO: Using git version 2.11.0
INFO: Building version 4.6.0a (11565) of org.telegram.messenger
ERROR: Could not build app org.telegram.messenger: Error removing sudo for org.telegram.messenger:4.6.0a
==== detail begin ====
dpkg: error: dpkg status database is locked by another process
==== detail end ====