VERSION: 6.0.6
DESCRIPTION: Post-build automated testing fails with error.
REPRODUCTION: run make test
EXPECTATION: Success.

My version of centos8.2.2004 comes with tclsh 8.5.9
I install 8.6.10 then re-ran make test
I now have some fresh errors:

[ok]: Detect write load to master
[ok]: Client output buffer soft limit is enforced if time is overreached
[54/56 done]: unit/obuf-limits (134 seconds)
[ok]: Master stream is correctly processed while the replica has a script in -BUSY state
[ok]: Test replication partial resync: ok psync (diskless: yes, swapdb, reconnect: 1)
[ok]: slave fails full sync and diskless load swapdb recovers it
[ok]: Slave should be able to synchronize with the master
[ok]: Detect write load to master

[exception]: Executing test client: tail: cannot open '+30' for reading: No such file or directory.
tail: cannot open '+30' for reading: No such file or directory
while executing
"exec tail +$from_line < $stdout"
(procedure "wait_for_log_message" line 5)
invoked from within
"wait_for_log_message -1 "Loading DB in memory" $loglines 2000 1"
("uplevel" body line 43)
invoked from within
"uplevel 1 $code "
(procedure "start_server" line 3)
invoked from within
"start_server {} {
set master [srv 0 client]
set master_host [srv 0 host]
set master_port [srv 0 port]