Postgres Display actual query error

[eqbalz]

I am running a simple lua script with sysbench like the following:

-- custom_reads.lua

function prepare()
-- Prepare the database connection
end

function event()
-- Execute your custom insert queries here
-- Example:
local success, result = pcall(db_query, "Select * from testtable TABLESAMPLE SYSTEM_ROWS(1);")

if success then
-- Code to handle success (optional)
else
-- Code to handle error
print("Error:", result)
end
end

function cleanup()
-- Cleanup resources after the test
end

I would like to display the actual error message if query is cancelled by database for example:

ERROR: canceling statement due to conflict with recovery DETAIL: User was holding shared buffer pin for too long. CONTEXT: SQL statement ...

However print shows something like this:

Error:  table: 0x4194aef8

Any suggestions?