Sometimes adding even a tiny bit of syntax hilighting to a log file can make it much easier/quicker to comprehend. Below are some recipes for Vim that make particular log files easier to read.

Most of these are performed either via :match, :2match, :3match, or via custom syntax files. [1] [2]

$Expect::Exp_Internal logging, in perl's Expect.pm

:match ErrorMsg /^spawn id([0-9]\+.*/
:2match MatchParen /^Sending .*spawn id([0-9]\+)$\|YES!!$\|^Spawned .*/