After updating package icu to version 65.1-2, the most recent thunderbird 60.8.0-1 does not start anymore due to missing:
libicui18n.so.64: cannot open shared object file: No such file or directory
(Same for libicuuc.so.64)
Trying to just use the version 64 shared libraries by symlinking them does not work around the problem, then thunderbird aborts with:
XPCOMGlueLoad error for file /usr/lib/thunderbird/libxul.so:
/usr/lib/thunderbird/libxul.so: undefined symbol: ureldatefmt_format_64